What is the next coolest thing to collect?

I've started to collect old mosaic trays from the 60's and Sasha Brastoff ceramics.

Drink coasters! There are quite a lot of fans for beer mats, but drink coasters are none the worse for collecting. You may specialize by some category, too (imprint topics, or stuff the coasters are made from, or manufacturer). E.g., stone coasters made by ThirstyStone, AbsorbaStone, or CoasterStone are very impressive

ThirstyStone coasters
AbsorbaStone coasters
CoasterStone coasters

P.S. Do not click the images. The search they offer seems to be a little faulty. I just liked the galleries.

Why are the funniest, most interesting posters on this thread being deleted?