How effective are unordered lists <ul>s as navigation in terms of SEO, accessibility, etc?

As far as SEO and accessibility are concerned, are <ul>s a good approach towards building simple navigation menus?

As point of reference, I try to test all of my sites through Lynx, just to help ensure accessibility, and <u开发者_开发知识库l>s seem to be the most sufficient in terms of their display in Lynx, but can this really be used as a good rule-of-thumb for SEO?

Most CSS navigation menus are built as unordered lists -- even horizontal nav bars are generally just unordered lists with the bullets removed and formatted a bit differently. See: http://www.alistapart.com/articles/horizdropdowns/

Consequently, I'd be very surprised if using them for this purpose had an adverse effect on SEO.