Yahoo! Site Explorer has added a feature that enables you to specify your URLs in a more search-engine friendly manner. If the site has been submitted to Yahoo and authenticated, you will notice a new button called Dynamic URLs.
If my URLs looked like this: http://example.com/store?prod=1&sid=23yadh56, I could use this tool to strip out the “sid” (session ID), which is a good thing. I could also rewrite some URLs such as http://example.com/blog?src=rssfeed to read http://example.com/blog?src=yhoo_srch.
It is a good option, but would I use it? If Yahoo! were the only search engine, then yes, but since there are three big SEs out there and any number of lesser engines, I’d rather use mod_rewrite at the Apache level to fix all my URLs. Read more about Dynamic URLs at the Yahoo! site.