In the case of DW, a virtual sheep would be an obvious choice and one could pay to "board" him/her with a particular account holder. Tracking where the sheep is, on whose account it has gone to, can be a bit of a game and have its own community as well as perhaps being some kind of alert on the site. The thing is, the person whose account it's on does not have to be the person paying to send it to someone else. People can pay to put it on their own accounts if they want.

Oh, interesting! I could see certain groups getting into this, especially if you could customize or choose the specific animal. VividCon's mascot is a llama, and Muskrat Jamboree's is a muskrat, and CON.TXT's is a duck, and Bitchin' Party's is a dinosaur, and the attendees and fans of those cons might enjoy that type of thing as a lead-up to registration and/or the con itself. All four cons have a high percentage of members who are exclusively using DW or using both LJ and DW more or less equally.