Go to Change Library or Configuration->System Configuration->Show Wired Ethernet Status and scroll down.
Ermm.. that's for the SoundBridge, and is not applicable to the PhotoBridge. For the PhotoBridge, if you go into Setup, the IP address should be displayed at the top of the screen. You can also go into System Information and see it there.
My Channels: http://roku.permanence.com - Twitter: @TheEndlessDev
Instant Watch Browser (NetflixIWB), Aquarium Screensaver (AQUARIUM), Clever Clocks Screensaver (CLEVERCLOCKS), iTunes Podcasts (ITPC), My Channels (MYCHANNELS)