A couple of us have been working on a comprehensive notebook web GUI for yt. It's not ready yet.
BUT! In advance of that, we've rolled a portion of that into something called the 'mapserver' into the development branch. This is a small, standalone webapp that implements a rendered-on-the-fly google maps interface in yt. To run it, just go into a directory that has some data, and run:
yt mapserver DD0054/DD0054
(where 'DD0054/DD0054' is the same thing you'd feed to 'load' in a script.) You can run with --help to see some options, but what it comes down to is that this will slice, but if you want to project, just do -p like so:
yt mapserver -p DD0054/DD0054
This will spawn a webserver on port 8080 which you can then hit in a browser. You'll have to forward an SSH tunnel if you're on a remote machine, but that's just a matter of logging in with ssh -L 8080:localhost:8080. When you're done, just hit Ctrl-C and it'll quit.
Anyway, I think this is pretty cool, and hopefully you will too. If you run into any bugs, report them either with 'yt bugreport' or by going to http://hg.enzotools.org/yt/issues/new .