I came across this Instructable for a mini boomerang the other day, and immediately got up to try it. All it takes is a little scrap cardboard from the recycling bin and about 5 minutes of time. Easy peasy. The kids thought it was fun, and Hubs liked it, too.
Launching...
Spinning...
I couldn't quite get it to return all the way, but I did get some sweet J-turns. Try it!