Smallest arduino possible - Tilt sensor

Hi all,

Thanks for the replies and apologies if I didn't give enough info.

My goal is to create "something" that I can store it under my motorcycle seat. It will sense if the bike is being fiddled about (moved/tilted effectively) and will send me a text message on my mobile phone.

Battery wise, I guess I could plug it in on the motorcycle battery, so I guess everything else is priority.

Size is a big issue, as it must be as small as it can get.

Does it make more sense now what I am trying to achieve?

Thanks,
Chris.