Custom CMS, pretty permalinks like commercial CMS

[admin]

I am currently whipping up a very basic CMS for a personal project of mine. It is as much for my own education as anything. One question I have is how do I achieve url's / permalinks without file extentions. I understand using get variables to pull data from the DB but how do you convert this to something like www.url.com/posttitle instead of something like www.url.com/?posttitle='blablabla.

Also on a slightly different topic can anyone point me in the direction of an EASY to use framework for developing sites that deal with memberships and member listings eg craigslist.

I currently develop within wordpress and am quite capable but am less familiar with OOPHP and custom CMS development from a base level.

Thanks in advance for any help or suggestions.