Since I've been using the Pre for over a week now, I've managed to get more and more familiar with WebOS and am enjoying it more and more. It combines many things found on today's hottest mobile OS' around - Android and iPhone OS. WebOS is highly underrated mainly due to the mediocre hardware it is being forced to run on, and the fact it's creators Palm have done a poor job of distribution and made many mistakes when launching. There are various factors why Palm's Pre and Pixi are not successful, but that doesn't necessarily mean WebOS isn't great to experience.
Both iPhone and Android users will be arguing why WebOS is inferior to their respective OS' but the fact is, WebOS has the best of both worlds and is all round more polished and the experience is very very impressive. Whilst Android may be the hot OS at the moment and iPhone OS catching up to the rest of the world with multitasking, folders and features the rest of the world's OS have had for years, WebOS has already been doing these things since launch and in most cases better. WebOS has many innovative features which give the impression, lots of thought has been put into making it a great way to use and a pleasure to experience.
Standby

The standby screen has been well designed to make use of screen real estate, with some very clever work. Whilst it looks like many other standby screens on many other devices and OS, touching a certain area brings up relevant information, both very responsively and with smooth transition. The top is similar to Android's with the exception of notifications, the top bar has quick access to toggle Bluetooth, WiFi and Aeroplane Mode, with information on battery life and showing the current date and time. Whilst at the bottom is where WebOS shows it's party trick and in my opinion has the best feature out of any OS out there today - notifications. WebOS has the best and least intrusive notification system. Whether it's an e-mail, tweet or SMS alert, it shows a little icon at the bottom, whilst also flashing the front button. These notifications just sit there whilst the user is busy occupied with other tasks until a little tap expands upwards into showing a little more information which also scrolls across, so you can read the header of an e-mail without having to open it. 3rd party apps can also utilise this function, for example a little weather widget which notifies of basic weather forecasts. It's very intuitive, smooth.

At the bottom sits the Quick Launch bar which can have up to 4 shortcuts (excluding the launcher) to your favourite apps and settings. This is very similar to Nokia's S60/S40 UI where shortcuts and in more recent updates contacts be placed there for quick access. WebOS shares a feature similar to the iPhoneOS, with the help of the physical keyboard, start typing anything on the standby screen and you're resulted with any apps installed, contacts, or the option to search via Google, Google Maps, Wikipeadia or Twitter or any other app which offers this function. The results are displayed and narrowed down the more keys pressed. A great way to launch apps, find contacts and gain quick access to features.
Gesture Panel
The gesture panel on the Pre is very simple, swipe left and you go back, swipe up and it opens up the multitasking option (the same result when pressing the front button, which has been removed on the Palm Pre Plus, and with good reason), where the user can close apps by just flicking them off the screen or switch between them. The great thing about this panel is it works universally, whether it be in the launcher, menus, settings or 3rd party apps, it's very similar to the button on the iPhone and the home and back buttons on Android devices. The gesture works complimentary with the Pre, which makes it easy to use single handedly or with two hands. It's an ingenious and well designed feature, something not replicated by any other.
Synergy
This is a great feature which enables one to integrate all their contacts from many different services into one manageable address book. The ability to sign in with Gmail, Yahoo, Facebook, LinkedIn and Microsoft Outlook is more manageable, very easy to setup and is more or less automated. This is a feature which has been utilised by many new handsets, INQ have done it with Facebook integration, Nokia's N900 has a 3rd party app which does the same thing.
E-Mail


Very easy to setup, great UI and support for HTML and multiple accounts, the e-mail client on the Pre and WebOS is one of the best out of the box solutions I have seen. Not only is it quick, but it renders all e-mail correctly and everything is legible. Multiple e-mail setup in one convenient place, it really is a joy to use.
Browser


Running on Webkit like many of it's competitors, the browser on the Pre is easy to use, has multi-touch and renders everything quickly. Whilst the main screen contains bookmarks to favourite sites - very much like Opera Mini does, this is much more enjoyable than Opera Mini, and some of it's competitors, especially those found on Nokia handsets. The browser is quicker, more smoother to work with and has been optimized to be compatible with Flash (10.1 support is coming from Adobe), Java and CSS.
Apps





The Pre comes with many commonly used and popular apps; Youtube, Google Maps and a very nifty looking Music player. Coupled with the great looking screen, GPS, accelerometer and multi touch, these compliment the already great looking interfaces designed for these apps. The Music player looks very slick, youtube has been well designed and the quality of the videos streamed is top notch.
What's great about WebOS is the community behind the Apps, although it doesn't have as many apps as Apple's Appstore or Android's Marketplace (some of that can be attributed to the lack of success of the handset) it does have some quality content. Whilst the Ovistore does struggle for quality of content and can be used as an example of quantity over quality, I have been able to find many apps which to this day still are not available there. As WebOS is built on Linux (like most of the mobile OS these days), and the code is very similar to iPhone's apps, the chance an app will be ported and the ease of doing so is very likely and more appealing The appstore isn't the only attraction of WebOS, with the installation of Preware (similar to iPhone's Cydia) tweaks can be installed to the OS and apps to give them extra functions, change the layout and behaviour.
There are tweaks to integrate a download option in Youtube, so if you liked the video watched, it can be downloaded to the handset for future play offline. There are tweaks to the launcher screen, the number of apps to display, the number of rows, the styling of text. Hacks to add more functionality to the browser, the music player (even a whole overhaul of the UI) are just some of the little tweaks which keeps this little community ticking. Very much like the Nokia N900's Maemo community, with the only difference being the apps and the OS here are more polished and less aimed at geeks and more for the masses. This means anyone can pick it up and start tweaking, downloading with ease.
WebOS is more of a complete OS than it's competitors and has been for a while. Whilst Android is generating a lot of hype at the moment which it deserves to, it still in comparison to the iPhone UX and WebOS UX is very bland. The fact that there are many different UI overlays created by HTC, Motorola and Sony Ericsson on their Android handsets speaks for itself. For functionality and features the Android may have some that are better than WebOS, but it lacks the eye candy which WebOS offers. Whilst on the other hand iPhone OS does have very good eye candy and an abundance of apps, it lacks many features WebOS has had for ages, both the Android and iPhone notifications don't come close.
With the right investment and effort put into WebOS it would easily be able to compete with Android, iPhone and Symbian / MeeGo easily.
Side note: Symbian is not even worth considering in this argument. Until MeeGo and Symbian ^3 are launched, it's a dead OS in my eyes.