When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I only carry two keys on me at this point, a car key and a spare key to the house since I usually go through garage and if I use front door there's a keypad. This would pretty much eliminate the need for me to carry keys at all.
Several years ago there was talk on a number of toyota and lexus forums of a wristwatch/smartkey combination but if it was ever available anywhere but Japan, the idea fizzled. That I would go for.