In our podcast Gadgets, I recently reviewed my daughter's rubber band loom. This Monster Tail loom, made by the same folks is a new favorite.
Smaller and designed to be handheld, my daughter brings the Monster Tail in the car, to restaurants, nearly anywhere she wants to ignore her father; it is easy to schlep. The Monster Tail has a more complex pattern of smaller posts than the Rainbow Loom, and thus allows for even more intricate designs.
The Monster Tail uses the same rubber bands as the Rainbow Loom and the same pick. For $8 it has provided countless hours of distraction for my darling kid.