Bram Fokke sent me a link to his website - some great stuff here. He's got an interesting tale to tell regarding his troubles with Bluetooth here.
You'll also find an introduction to Bram's "Visual Lego" - from his site: "Visual Lego is a library for .NET which allows controlling your Lego Mindstorms NXT Brick from your C# or VB.NET application using the Bluetooth link. This allows you to combine the power of .NET with the power of Mindstorms NXT! The first version is nearly finished. When it's done, I'll post it for download."