Where to use Bitcoins?

Don't want to go off as rude, but have you tried Google?

What are you looking to spend buttcoins on?

You can buy games on Humble Bundle by paying with Bitcoin.

Just looked into it, looks like Green Man Gaming (and Playfire) accepts Buttcoin. Newegg and Tigerdirect accept them as well, though they're more related to hardware for building computers (including gaming machines).

Other than that, I was too bored to keep looking.

Buy usd .

With all the poll selections, you didn't include "Humble" or "Bundle", which is your answer. ;)