Caution: the server for the distributed object networking was written only last semester, and it still is pretty untested, and there's no documentation. I just fixed a serious bug in panda3d 1.0.1. If you're willing to put up with bleeding-edge code, then here's a little information:
Download my lecture on "Networking for Games (Continued)" - not the first lecture on networking for games, but the second one.
Also, look at the panda sample program "chatroom."