I think (and I have nothing to back this up except for a few isolated cases on my sites) that if you use an .html extension instead of a .php extension your dynamic pages will stand a better chance of being indexed.
Again, I could be wrong, and I have zilch for data, but I've had dynamic pages that use .html extensions with a ?var=data type stuff after the page get indexed. (
www.domain.com/page.html?var=data for example)