[niky]

Is there any real SEO benefit from simplifying my PHP urls to shorter, neater urls (with mod_rewrite)? I want to do this mostly to make my site look nicer - but if it's good for search engines, then all the better.
Is there any reason NOT to make shorter URLs?

[T2DMan]

Many reasons to have more relevant url's. the only reason for keeping string url's is if you can't be bothered making the effort to change. String url's can work great for SEO, but generally their are also many other issues that exist. When you decide to use mod rewrite, you are more likely to only have one url per page. Or at least you need to make a conscious effort to only have one per page. Make sure that the old url's 301 redirect through to the new rewritten url's.