Mod Rewrite and search engine optimisation

There has been a lot of talk recently of so called mod rewrite and what it is and how it can be used to help optimise your search engine performance.

It is just a method of re-writing URLs so that they do not appear as:

thisurl.html?id=x&yid=352&posid=5436 and so on

To:

this/nice/url/here

Or similar.

The advantage is that many search engines do not 'like' dynamic URLs or find them harder to crawl.

Therefore having flat or static looking URLs can help a search engine to crawl the site deeper and more regularly perhaps too and therefore can help impact your search engine performance overall.