I have some nice avatars that I laboured over in the character editor, and I've grown rather attached to them. Is there any way at all to export them? I'd like to be able to bring my avatars with me when playing Rock Band at my friend's place.
Save your profile and save game data to a USB flash drive and then bring the flash drive to your friend's house. When you arrive, plug in the flash drive and you should have access to your profile and any save games you have saved to the drive.
The advantage to this over simply saving the save game to the cloud storage is that it is much easier to login to a profile from the flash drive than to download the profile to the other system, and has the additional advantage that you don't leave you profile behind where someone might do something with it that you don't want to.
Or, split the difference and put your profile on the flash drive and the save game in the cloud.
If you have Gold you may be able to save your game to the cloud and then log into your XBL account at your friend's place. If you can save it to the cloud you will get your avatars.