@rappa: Thanks! I used my new Cannon S5 IS for the photos, it has a super-macro mode which is great for electronics. I took my XBee boards apart for a robotics project, but I'll breadboard one up this weekend and take a couple photos. If you're just doing point-to-point stuff, I'd recommend sticking with the XBee-Pro Series 1 modules if you already have them. The ZNet modules add Mesh networking functionality which you may or may not need.
@cels: Mesh networking doesn't require any different code, it is transparent with the ZNet modules. The only difference is that there are additional AT commands for working with the mesh network (like for sending data to a subset of devices on the network). Check out this Knowledge Base Article from Digi about doing simple point-to-point communication using 3 XBee ZNet modules as a mesh network.