I have a roadID, wrist band version, actually jusst got it yesterday. Since i typically don't run with any ID, I figured it would be a good idea to have some on me since I have medical issues. When I bike, I use a camelback, so it is no big deal to carry my wallet. Be advised for those who carry their ID's in a seat pack or other place, if you are seriously injured, EMS may not spend much time to look for an ID hidden in a seat pack or inside your helmet etc.. Also depending on the accident you can be seperated from where your ID is too.