The Canon G11 has been replaced by the G12. They're very similar cameras in almost every way, but the G11 costs about $100 more than its replacement, so we say skip the G11. It's still a great camera if you can find one for a deal, though. Here's what we had to say about it when it was in production:
The Canon G11 is an advanced compact camera intended for serious photographers. It offers real power and advanced features like the ability to shoot in RAW format, as well as standard JPEG, and some of the most intricate manual controls you can find on a compact camera. It's a great camera for enthusiasts, but also works as a backup or supplement to a dSLR system.