Wow, I know you've heard it before, but Ravelry is GREAT. I would like to point a few things out, though, that seem to have been glossed over in other reviews, which are mostly along the lines of YAY KNITTING ORGANIZATION SOFTWARE.
Casey and Jess are brilliant. Not just for the original idea - I'm sure we've all wished for something to organize our things. But the execution is fan-freaking-tastic. I dunno what companies they worked for before doing Ravelry full-time, but I bet their former bosses are weeping into their disgusting office coffee that their programmers are gone. Not only is this knitting/crochet organization software, but it's put together in a brilliant, well-thought out, intuitive way that is crazy-easy to use. The thought that went into this monster database is astounding. I work in the tech field, and have seen examples of really good stuff, and we've ALL seen examples of really bad stuff. This stuff is Really Really Good. The execution of the idea, the search functions (complete with easy searching help, if you want to narrow things down), the information you can store... Well, Jess is a knitter, and Casey is a jewel. This is technology at its finest (IMHO) and I hope this site has them rolling in money and excited to do more projects along this line.
I'm not trying to rub in that I just got in, I am just trying to give some semi-public kudos to these people who not only worked very hard on this, but they did it RIGHT.