The mod rewrite of my urls is done by
vBSEO as well as a lot other SEO optimizations.
However vBSEO costs 149$
There are other free mods out there that do the mod rewrite of the url but not all the SEO options you get with vBSEO.
There is a big discussion about if it is worth the money or not. 50% say it is, 50% say it is not.
I bought 2 licenses mainly because of the mod rewrite of the urls and the total compatibility with mods and add ons.
I tried the free mods and they all had their flaws.
So I can say for myself, that for me it was worth spending the money.
But that is a personal choice.