I've cc'd our hardware engineer to give you the latest scoop on this--John, what is the current thinking on serial mice vs. kb's and boxes in terms of timing? This might also help--we have just finished developing a compact box configuration which allows you to place 2 single button boxes--one on either side of the keyboard for doing dichotomous judgement tasks such as an IAT, LDT (lexical decision), etc. Would be easy to carry and they would be as accurate as can be. John can give you more info on this if you are interested (via chapman@...).