Why do you use proxy websites?

There are different purpose of using proxy websites. Some people use proxy websites for surfing internet securely so that other internet users cannot see their IP address. There are some people who use proxy sites for bypassing community websites like Facebook, MySpace, Orkut and other websites from the restricted internet network which use network filters.

So, still there are some proxy users who use proxy sites just because to change their IP address because the particular IP address cannot be used in some classified ads websites like Gumtree, Craigslist and other webistes. So, now why do you use proxy websites? If you have any new purpose of using proxy websites, then please do share.