Wallpaper borders are something to think seriously about. Before you put one up, even a really cute one, consider whether you will EVER move away from your house and want to sell it. We loved a house here in Beavercreek, but didn't buy it because there was too much wallpaper to remove.
We have a very cute border in Joshua's room that was there when we moved in. It was great for Josh, but now we are moving the new baby into his room and Josh is going to bunk with Ben. So, the sports border has to come down. I have spent 2 hours scraping at the ceiling, and have sore fingers and arms, and am about a quarter of the way through. It is going to take longer than painting the room!
So, really think about it.
By the way, I painted the room the most cheerful yellow color you can imagine. Yellow is definitely my favorite color. Such a happy room!