Not sure how you'll take this question but...
Whenever I try to make my URLs look pretty I always end up messing around for too long and it's simply not worth the trouble. But the end effect is good if it were a simple task.
So what I want to do is create a method which in the end would achive something like...
index.php?do=user&username=MyUsername //This becomes...
/user/MyUsername //...that
index.php?do=page&pagename=customPage //And this becomes...
/page/customPage //...that
index.php?do=lots&where=happens&this=here //This also becomes...
/lots/happens/here //...that
index.php?do=this&and=that&that=this&and=some&more=too //And yes...
/this/that/this/some/more //This becomes this
So then I just make a nice .htacess file that I'll never have to look at again. Everything will be better in the world because we have pretty URLs and my head didn't hurt in the making.