My daughter is having a Monkey themed birthday party at local water park. I found kits for beach ball invitations on Oriental Trading's website. It include an ordinary small beach ball with the invitation info (time, place, etc.) printed on them and a little waterproof container. The idea was great, but it was a little plain. So when I ran across these cute monkey beach balls, I decided to just make them myself. They only cost about $1 each to make, which is about how much the plain ones would have cost too. I don't think that is too bad. I got the little containers for 50¢ at Party City and paid $5.99 for a dozen for the balls from Oriental Trading (which is about 50¢).
To get started you will need StazOn ink, sharpy pen, an invitation stamp, water proof container, and a beach ball. You could use an evelope if you can't find the little containers.
Stamp the image onto the beach ball and write your information using the sharpy. This works much better if you don't blow the ball up and use a flat surface to work.
Add a label and you are done. You CAN mail these in this container. You will need to make a mailing label. Also, take the string off and put it inside the container. We are hand delivering to our friends that live near by and mailing the rest. I used a monkey stamp, put their name on it, and added a little line that says "inflate for the date". I hope they like it!