I still think You'd be better off with an N900
Camera, GPS, accelerometer and development toolkits all rolled into one.
But since it got and continues to get very little coverage by the reg and is never mentioned in comparison with the Jesus phone or Androids that is possibly not surprising btu a little sad for such a fantastic piece of kit.
It's already been used to control and track another 900 attached to a kite and record skateboard tricks to give points showing its versatility to being used for any purpose and though it's slightly chunky I am sure it's lighter than 3 separate units.