hmmm... As do u use AdobeRGB or sRGB? In the event that the monitor is properly calibrated, monitor support AdobeRGB such as Dell U2410 (Adobe RGB 96% coverage) and using professional photo editing s/w like CS and LR, is it still better to use sRGB?
Calibration is independent from any colour space.
You can use AdobeRGB if you like, just set your camera and all your programs accordingly. But for export to Web you must set the colour space to sRGB and make sure the ICC profile is embedded (LR and PS will do that as default). The Internet 'speaks' sRGB.