i know some crawlers still dont like dynamic pages that much. but the big search engines handle them pretty good now.
like for example, links like this
index.php?page=foo
would prob be fine for the majority of crawlers
but
index.php?page=foo&bar=baz&s=t&b=c&etc.......
may not go so well in some of the smaller crawlers. but the crawlers that have trouble w/ long query strings, prob arent giving its user the info they want, and as such prob arent used by that many people either.
im no seo expert, but i think as long as your links arent extremely dynamic, and you allow your site to be browsed without cookies enabled, you should be fine.