On Decor8 there is a contest going to see who has the coolest idea for a hobby if money and time were no object. I posted on there that mine would be to go around the world tasting all of the different cakes of the world and documenting them in a book. Cake is by far my favorite food.
But another hobby that would be kind of fun, that's slighty more feasible would be wrapping paper collecting. I'm trying to be better about sending gifts on time (still haven't gotten my cousin a wedding gift from last summer) and writing thank you notes when people send me gifts. I feel like a more mature person when I do these things...some people get married, and buy houses. I wrap gifts and write notes to feel mature.
From mr.french.com. Each roll is only $6.50 and they've got everything from engagement paper to dogs! Love the dogs.