I took my own advice - A week or two ago I linked to a tutorial for some adorable Super Mario coasters. Shortly afterwards, Jake decided it would be OK if I made him coasters for his birthday. He's been begging for geeky home decor for so long.
Here's my version!
They look great, and they're holding up to all the abuse Rei can dish out. She killed our last set of coasters, so durability is imperative.