Make "the Force" the keeper of your key.
Another Great Minimalistic Lego Key Hanger
DIY Lego Key Holder: Lego part number 3176 already has a convenient hole.
Picture of Lego Key Holder and Note Clip
Day 13: Lego Key Holder #30DoC
Lego key holders diy...would totally work here!! We all have Legos on our keys!!!
Lego key holder. Also means keys can be easily separated to give out/hang up and clicked together in your bag for not getting lost! I would probably use proper lego though!
The folks over at the blog for a self-setting rubber product called sugru have been busy finding new and ingenious ways to use sugru, like this clever LEGO cable and key holder.
Fridge Keychain Holder v.1 by Jameson42, via Flickr