Well, I noticed no one mentioned Mason, one of my favs, so I thought I'd bring it up (though the poster already mentioned it).
If you haven't looked at it,
the mason book is a great place to start poking around.
A lot of the common things you'll need, like sessions, can also be handled very easily through something like MasonX::Request::WithApacheSession
It's a shame there isn't a Mason Cookbook. Maybe I should write it.