The i200 runs Windows Mobile 6.1, the latest version of Microsoft's Smartphone OS. No one is going to argue that the ever clunky Windows Mobile is the perfect phone OS, unless they live in an institution with padded walls, but at least 6.1 does offer some extra functionality. For example, SMS messages are now threaded making it easier to keep track of conversations and text editing has also been improved so you can now cut and paste between emails, SMS messages and text boxes in internet explorer (a very small poke in the eye for the iPhone).
Samsung has also included the Office Mobile bundle complete with Onenote, a kind of sketchbook that lets you combine text, voice and picture notes into a single document. You don't usually get the Office Mobile bundle on non-QWERTY smarphones, so its presence here is a bit of a boon, especially as it lets you not just open and view Word and Excel documents, but also edit them directly on the phone.
You also get a few of Samsung's own mini applications including an RSS reader and a content manager that gives you fast access to your documents, pictures and also the memory card. In fact, you're likely to have to make considerable use of microSD cards, as the phone's onboard 20MB of free memory isn't exactly bountiful.
In use, the i200 feels relatively sprightly for a Windows Mobile device. Screen redraws are pretty much instantaneous and there's not much waiting around when scrolling through menus or performing other day-to-day task. Thanks to the support for HSDPA picking up email or using the browser when you're out and about is also fast and responsive. However, the phone lacks Wi-Fi, which is a bit of a travesty in this day and age when almost every other smarpthone on the market has it built-in as standard.