Ask HN: What's on your key chain?
Any interesting tools or flash drives you really like? Something else?
I've got the key shark and love it: http://kk.org/cooltools/archives/8325
Ti Widgy Pry Bar from County Comm: http://www.countycomm.com/titaniumwidgy.html
I would say the most interesting thing on my key chain is an actual chain - switched from a ring to a ball chain (use aluminum tape to keep it from coming undone.) The ball chain allows the key s & flash drive to lay much more flatter than using an ordinary key ring.
Second to that would be a San Francisco Public Library card, which allows me access to their extensive catalog of on-line books.
I have this (http://www.amzn.com/B006W8U2WU) flash drive and love it. It's much sturdier than the typical plastic drives and has a great simple design. Unfortunately it is only USB 2.0, so I wouldn't recommend it if you use computers that support USB 3.0.
Just keys. Anywhere that I need to get a bottle top off there is usually a bottle opener and I never use a flash drive (Cloud ftw).
My old Pentium 4 http://imgur.com/ZTXkb8L