Just a quick question for anyone out there in blogland: Have you ever used C#/.NET for any equity, fixed or other securities trading?  Have you used it to interface with an existing app like TradeStation?  If not, how did you use it?  Have you built any sort of automated trading system?  I'd be interested in hearing your experiences from a technical and/or business perspective (either here in comments, or privately via email at chadich@yahoo.com).

(Disclaimer: This is a private research project that has nothing to do with my job at Trading Technologies, which makes extremely good trading software for serious derivatives traders, not that I'm biased :)