I actually have small hands for a guy, at least one being 5'11". My cock is longer than my hand, 8". It was funny, a guy from work wanted to see my wedding ring when we were all out one night. I took it off and handed it to him and he promptly noted that I had a small finger and must have a small dick. My wife put him in his place right away, especially given the strories we had heard about him.
I think there MAY be a correllation between hand and foot size and cock size, at least if you are taller than say, 6'5". but its definitely not conclusive. I've had several women, who have been with much taller guys (and thus longer hands and huge feet) tell me that I was much bigger than them (even bigger than someone that was 6'6"). So, while hands and feet may be a sign, I don't think it is the end all, be all sign. I mean Christ, there are guys on here that are 5'5" that have pretty damn big dicks (if their stories are true).
Personally, I know a guy that is 6'1" that has nice fat long fingers (from my nail tech wife) and has a cock that doesn't get over 4 inches long on his best day (he confided that to her).
CONCLUSION: no correlation!