From what I've heard, It's usually such a pain getting older and newer stuff to agree on the type of encryption to use.

I actually went without any encryption since I wasn't going to be doing anything on it that would need to be encrypted. But as I had said, the wireless router is set up to limit wireless access to just a list of specified MAC addresses... so the network itself is not totally wide open. Unless someone goes to the trouble of spoofing one of our MAC addresses, they can't just hop onto our network.

Also, we actually don't do any of the really important stuff over unencrypted wireless. For those kinds of things, we just use the machine that's hooked directly to the router via ethernet. Then we don't have to worry about who might be snooping on our wireless packets.