My keys are boring and always get lost! I leave them at work, neighbours, friends, in my other bag, somewhere in the house, all places where they should not be at all.
In the eihgties i used to have one of those keygadgets that, when you clap your hands, your keyholder makes noise. Nowadays i don´t see them in shops anymore. Then i bought huge keyhangers so at least i could easily feel if my keys were in my bag or in my pocket but they got trapped too many times between doors, etc. and so also these are gone.
Last week i saw these happy mushroom keycaps in a store at Groningen and hmm..... why not?
P.S:Do they have such things to keep my cellphone warm? I lost it lately inside the freezer!