I have my own micro-framework I made for bigger projects since I can't stand any of the main ones (though I've heard good things about Yii, that's probably where I'd go if I felt mine was inadequate). As with most things, the context of what you're doing matters. I'd guess most websites don't really need a framework, though once you start doing REST-y stuff that's when you should probably look into it. (Plus you get nice looking URLs for free when you go down the any-size-framework path.)