5 things to do with a t-shirt signed by Neil Gaiman
Write "pay to the order of [you], lots of money" on it, take it to the bank, try to convince them it is a cheque and cash it.
Starch it heavily and put it on your bookshelf
Run it up a flag pole in your front yard. Delcare yourself soverign lord and ruler of the republic of Neilgaimaniana. Invent national dance, anthem.
Prop in a crazy vodoo ritual to steal Neil's powers.
Wear it to impress girls.
--a couple of random readers, on Neil Gaiman's blog.