ADHD and Caffeine?

I would be interested in hearing from anyone who has paid particular attention to how their child with a dx of ADHD responds to caffeine-more active, less active, neither?

There are some interesting points of view related to caffeine and ADHD. I have allowed my son with a dx of ADHD to drink coffee and soda in moderation and have not noticed an increase in his symptoms but I can't say that I have noticed that much of a decrease either. So I am curious about others experiences.

Here are some interesting web sites relating to caffeine and ADHD that I have enjoyed reading.

http://newideas.net/adhd/adhd-diet/caffeine
http://www.addmtc.com/caffeine
http://www.myomancy.com/2006/07/caffeine_and_ad