When I've looked at Web frameworks in the past (not just in Python) I've been disappointed by their lack of a resource-oriented focus.
RESTafarians like myself typically want URIs to map to objects that then simply implement HTTP methods (assuming HTTP is what's being used—REST isn't limited to HTTP).
I was aware of mnot's Tarawa experiment but hadn't seen that sort of approach adopted in any other projects.
In Leonardo, I started down the path of being resource-oriented but it is still somewhat half-assed.
In Demokritos, I wanted it to be a focus from the start. This makes a lot of sense with the Atom Publishing Protocol because APP is really just a subset of HTTP. You have to be able to handle PUT and DELETE verbs, support reading and writing of HTTP headers and be able to return proper HTTP response codes.
(Incidently, my understanding is that something like Ruby on Rails is a bit of disaster in this area.)
Although I haven't released a version with this yet, I've refactored out the general resource-oriented HTTP parts of my Demokritos code. You can take a look in the svn repository at webbase.py for the module and server.py for a specific example of it in use for the Atom Publishing Protocol.
Since I started on Demokritos, web.py has come out. It takes a similar approach, does a bit more (especially in dispatching - where webbase.py currently lacks), but I think I still like webbase.py more.
Very recently, I've started talking to Sylvain Hellegouarch and it sounds like CherryPy might increasingly enable a RESTful approach so there's a possibility at some point that Demokritos could move over to CherryPy (which would probably mean Leonardo would too if Leonardo becomes a layer on top of Demokritos).
In the meantime, check out webbase.py. I welcome feedback on it—especially from other RESTafarian Pythonistas.
UPDATE (2006-02-10): The link to webbase.py above is now incorrect. See pyworks.web.