Popular private torrent tracker FunFile.org is now open for signup. FunFile tracks around 8500 torrents and has 44000 members. They have opened signups till they reach 50000 members and will further open signups till the member count reaches 100000 in the second phase. It's a decent tracker with average pre times and a nice, clean interface. Check it out.
Site Name: FunFile
Signup URL: http://www.funfile.org/signup.php