i think its a good concept, but in reality i doubt it will do much good. if it does alert your mobile and you left your bike somewhere u could not see it, thats already enough distance for the thief to take off with your bike. it would take less than a minute for a group of muscular twats to lift a bike into a van and start dismantling it on the drive to wherever twats go. even if it did alert your mobile, i doubt you could get to ur bike and catch them in the act before they take off. and no matter how small it is, thieves know exactly what should be on a bike and what shouldnt. the moment they see something suspicious, they will rip it off. not to mention how easy it is to take apart a bike. cars give a lot more space to hide things but a bike is pretty much exposed. to me its just a marketing thing. like lo jack in the states. best bet is insurance and a prayer.