I have made a C# library for interfacing with calcnet. You can get it at ticalc: http://www.ticalc.org/archives/files/fileinfo/435/43531.html. You can use it to make software for your computer that interfaces with calculators over globalCALCnet. Here's a screen shot of a chat program I made using it:

Let me know if you have any questions or end up using it! I'd love to see some projects made with this (I think sircmpwn is already thinking of something, maybe he'll share ).