Ultimately, you can make your own choice and I think most people here
would say they were OK, especially fresh, uncooked snow peas.

But some make a strong case for their exclusion.  The best I have seen and
which refers specifically to snow peas as well as all other legumes is

http://www.earth360.com/diet_paleodiet_balzer.html

This site is a good read anyway and well worth a visit.

Keith