TIK : Thin Is Key – The World’s Thinnest Keychain
The TIK is the world’s thinnest and lightest keychain. It is the most literal sense of the word as the keys are held together with a bike chain! By doing so, they eliminated all but the necessary part of the keys.
You can add as many keys as you need and even add other things, like bottle openers! The cost is $39 for up to 4 keys and $2 for each additional one as they are built in-house. For the weight weenies out there: it eliminates 40% of the weight with a standard keyring.
Check out their website for more info!