Maybe not technically yet, but in essence (or soon): yes, I'm pretty sure that's going to be possible easily. Can be used for example to run a local currency or niche currency or game currency or whatever.

EDIT: actually lol, I think it might already be possible: I managed to extend trust for "1 FAV" to someone (you can actuall enter stuff into the dropdown boxes).

Would someone trust me (rpH3zuMch2GrrYX724xGWwbMGwiQ5RbSAU) with 1 FAV, please, so I can try sending some?