Get your more versatile European toys to plug in to your US outlets.
Just plug the round Euro plugs into the back of the adapter, and into the outlet it goes. Just keep in mind that it doesn't alter the voltage. If your European toy needs 220v, it's going to have a hard time operating on 110v. However, many toys already step down the current from the wall, and may be 110v compatible. Check to make sure that your European toy can handle the 110v.
European to U.S. Plug Adapter Specs and Benefits:
Measurements: 1.3 inches wide, 1.6 deep, 0.5 tall
Material: Plastic, metal
Note: Converts standard European plug into standard US plug