Object Oriented Programming : A simple.. "test"

I’m trying to learn a bit of OOP, I checked out this AWESOME site (here) which I found in the forums of course, and it really got me interested in it. I read through it all once, then went over parts that gave me a little trouble. I"m no master of it of course, in fact I’m a huge newb at it. I was looking for some sort of “challenge” i guess that involves OOP. I saw one on here by Senocular(Spelling?) and I was going to give that one a go but it seemed to advanced for my knowledge. So if someone has a somewhat “easy” little challenge I would like to hear it, because I’m trying to find ways to practice using OOP. Thanks a lot if you have any ideas.