Unless your final destination (print shop, etc) wants AdobeRGB, you're safer staying with sRBG. Most corner stores will use sRBG, it's widely supported by browsers if you're posting on the internet.
If you want your shots to look good (or at least what you think they'll look like) contact your printer before you get your images ready. They'll advise you color space, DPI, etc. The closer you match to them, the less work you let a computer do.
Personally, about 80% of my stuff goes to the web, and 20% goes to print. I use MPIX for everything exept book publishing (which almost always required CMYK, the bastards). MPIX uses sRBG so that's what I use.