If you like postsecret, you might like ThanksCards. It's the same concept, different theme - thanks and gratitude stories for things people have done that made a difference in people's lives.
If you like PostSecret, you'll love www.SecondChanceOnline.blogspot.com. People anonymously post the one thing they would change if they were given a second chance. You won't believe what people are posting! CHeck it out and then post your own!
I recently did a PostSecret lesson with my Korean high school students. We discussed some of the secrets in class, and then for homework, students made their own postcards. They did an amazing job!