Currently Being ModeratedDec 27, 2012 3:27 PM (in response to JoshCunningham)
See this section in the GarageBand Help:
You can either share your song to iTunes as a project; then it will be synced to your mac, and the enxt time you sync your other iDevidec the project will be uploaded to them.
Or enable iCloud in your GarageBand settings; then you can share your project to the cloud and you can import it on your other iDevices without detour to your Mac. (I would only share a copy of the project - sometimes the transfer to iCloud takes a long time).