Best Robo kit for 10 yr.old??

People will have a lot of suggestions, but this question can't be answered unless you provide some idea of the price bracket you're looking at. Under $50, $50-100, $100-200, more? There are just too many kits, and too many levels -- even for a 10 year old -- to answer this question without refining the criteria.

-- Gordon Author: Constructing Robot Bases (Forthcoming) Robot Builder's Sourcebook, Robot Builder's Bonanza

ide recommend the lego mindstorms range as it is something that many kids already have skills in (lego) with a range of wat can become complex robotics as well if u choose for it to be.

If your son has never done any computer programming and is a newbie to simple mechanical machines (e.g. worm gears, gear ratios) then consider the introduction Lego Mindstorm series like the "Discovery" kit. Another way would be to send your son to a summer camps that teach robotics. Exposure to others with the same interest would probably be helpful.

For a really cheap start - beam robots

For something that reusable multiple times, will allow him to redesign = as many times as he wants Lego robots - lego mindstorms. If he already has lego he can use it with the mindstorm kits.

Probably worth your while finding out if there is a local robotics club near you.

Alex