It doesn't matter how ultra-thin your wallet is, your pant pockets will still be overflowing if you're cramming a huge set of keys in there. But even if you move everything onto a single ring, there's still no way your current set of keys will get as compact as the TIK keychain.
Made from a re-purposed bike chain, the secret to the TIK's compact form factor is to do away with the heads on each of the attached keys. This dramatically reduces their size, without reducing the amount of leverage you have when it comes to opening a lock since the rest of keys on the bike chain step in to fill that role.
Even though the TIK can flex and they keys are free to rotate along one axis, the whole thing always remains flat in your pocket. Which means you could even stash it in a wallet, if you hadn't already downgraded to a paper-thin card holder.
There are a few catches when it comes to the TIK, though. First, it's a Kickstarter initiative, which means if it doesn't reach its funding goal of $23,000, it won't be going into production anytime soon. The other concern is that you'll need to specify exactly what blank keys you'll need installed on the TIK you ordered, and then hope that your local locksmith doesn't screw things up when cutting them.
There's a small chance the TIK won't fit into the automatic key cutting machines in use in many stores. And if something does go wrong, you'll need to order a replacement blank, and trust that you'll be able to reinstall it on the TIK chain by yourself. That won't be so bad—if you've fixed your own bike chain, this is a piece of cake. [TIK via Notcot]