You can find "dirty sites" searching with a search engine, such as Google for example. Whether a site is blocked or not depends on whoever blocks them - for example, a firewall installed at your school.
List of likely unblocked game sites: crossify.com ninjamadness.com makeskoolfun.blogspot.com breakontheweb.com oacie.com actionmadness.com breakontheweb.com miniclip.com thecomplex.weebly.com
Joost.com
There are websites that will change your URL into something different so you can access sites the a content filter has blocked. Go to this website for a list of proxy sites: http://www.tech-faq.com/proxy.shtml If none of those sites are unblocked just search Google for Proxy sites and try ones till you find one that is unblocked.
yo dirty ahh
The websites that are blocked at schools will vary school by school. Remember: these sites are blocked for a reason. If your school wanted you to look at them, they would let you.
Tyrone's Unblocked Games
There are loads of games site, just doing a basic Google search would lead you to a few. A few I've used in the past are ActionMadness.Com and BreakOnTheWeb.Com - Happy gaming!
There are loads of free games, a few are like actionmadness.com and breakontheweb.com - enjoy mate. Just Google search and you will find loads of sites.
Wait until you are unblocked by an admininstrator.
You don't need to unblock any just uninstall and install again.
A few I have used in the past, but try Google searching http://www.breakontheweb.com http://www.actionmadness.com http://www.crossify.com
If you cannot list on ebay, you can list items on craigs list or other auction sites. You can use google to search for more sites.