For my son's 5th birthday we did an Olympic Birthday party.  The invites had a border with people doing all sorts of olympic sports and int he center it had the olympic ring.  (you can not find anything with the rings on them, I had to make everything, Copywrite laws) And it said "Please come to Michael's Olympic Birthday"  For decorations I bought plates in the colors of the rings and cut out different sizes of circles and put them all over.  For the cake I made circles and sat them in the center of Happy Birtday. On the internet I found a pattern to make an olympic torch.  It said Sydney and the year on it.  I imported it into a program and changed that to say "Michael's Olympic Birthday" and put the rings on it. We had a relay with these.  We had a discuss throw and some other olympic games. After the games each child came up to receive his or her medal.  I took a picture of each child getting their medal. I also order plain white sports bottles that I put each child name on.  For the Thank yous I took the pictures taken while getting their medals and cut them into a circle, I then cut a gold piece of cardstock into a circle and glued the picture to it.  On the back I printed (in a circle)  Thank you for coming... Then attatched a red/white/blue ribbon to it turning it into a medal.