If you are in the UK, and you are looking for a really cool, do-it-all site, with classifieds, event announcements, blogs, and groups, then you need to check out itsmymarket.com.
It is really a neat site and they have competitions, too. So far, it looks like - there have been two competitions, Cambridgeshire's Beautiful Pets and Norfolk's Beautiful Pets. The pictures are so freaking cute!! And the winners won a bunch of money - money is always good!
I like this site, because lots of the things you might log onto the internet to do, are all in one place - it's really cool!
If you're in the UK, you should definitely check it out!