Donate books!
Send The Cat In The Hat a Birthday Card
& He'll Send Books To Underprivileged Kids!
Get the code to repost this here!
And, as angry_biscuit says:
"Remember, it's absolutely free, you're not signing up for anything, and it only takes about a minute of your time (well, more if you're picky about your colours like I was). How often do you get a chance to help someone in need that's absolutely pain-free and actually kinda fun? Now get to it! :)"