The previous posting on this subject was actually an excerpt from my C-Scope website I've written a year ago. Thoug still valid, things have changed since then. (Ofcourse, you should say. Things change on a daily basis, and a year is 365 days, so..)
First there is the release of .NET 2.0, and .NET CF 2.0. The .NET CF is part of the new Windows Mobile 5 ,but you can download and install the free distributable on any Pocket PC. Drawback is that there is no freely available Windows Mobile 5 emulator anymore, so you need an actual device to test your applications. Good news is that a compiled .NET CF application will also run on your desktop, so it's not a major issue .
Second there is the new, updated release of SharpDevelop, the excellent freeware C# IDE. that now supports (and even requires) .NET 2.0. I've just started to use it, and it's amazingly easy to create a .NET Windows forms application that runs on your desktop, and with some modifications it also runs on my Pocket PC. Next time I'll tell how.