[whpalmer4]

Are you using 10.4 or 10.5? It's easier to configure the 10.5 firewall to allow OmniFocus through; with 10.4 you need to do some puttering around to get OmniFocus to always use a specific port (which you can then allow through the firewall). It shouldn't be necessary to turn off the firewall entirely.

I don't know anything about SplashID.