It's been done in the Paradise Kiss community parakiss at least twice, and it's always been fun. Basically what happens is: everyone picks a character, gets assigned to someone who picked a different character, and then they mail each other small packages of little things that the character would use/want.
For example, last year in the Paradise Kiss swap, I got paired up with the lovely Meredith _secretpassion_ . She picked Arashi and I picked Miwako. I sent her some rock type things Arashi would like (a note book, some hair gel, safety pins, hair dye...etc) and she sent me all sorts of cutesy Miwako things (nail polish, lipgloss, an ADORABLE totebag I still use...etc).
Anddd I just remembered I had pictures of what she sent me on facebook!
There were also money levels for people who could afford to buy more/less, that way everyone could participate!
Anyway, it's lots and lots of fun. Anybody interested?