I have an X3 chip, running XBMC as my dash, also have Evo-X installed. Looking for the best way to take a screenshot of an Xbox game, so I can then grab it via FTP and view it on my computer, post it online, etc. I don't mind installing another dash or utility if I need to.

There is a way but its highly illegal soooo no. You have to get a capture card, or tv tuner. But pretty much its a device that allows you to play video and such from like your tv on your computer and you can record it or take a still shot. Also a one worth buying (if you can get a good one) can run anywhere from $50-$200. Also I don't know if the big wigs here consider the screncap package for halo 1&2 "modding" so I guess I can't talk about that. Sooo yea. Only thing you can really do is take a screenshot of your dash when your in your dashboard. Its like you have to press the black button or something on dashboards like Evox and AnodX.

you need to use the sdk

More commonly referred to as XDK (XBOX Developement Kit). And yes that is one option. It comes in 2 parts, the SDK is installed on the PC and XDK installed on the xbox. Really alot more trouble to go through just to take screenshots.

There are also a few other programs out there that can do it, forget the names of them though. Maybe XBOX capture or something.

Or as said above you can just get a capture card (which is definatly the easiest route to go).