Ah, I missed that the 1100 supports HPNA; though I've never used HPNA myself, so I don't know how well it works in practice, phonemonkey explained it correctly. Since your 2Wire already knows how to talk to HPNA equipment, all you (theoretically) need is your 2nd computer with an adapter plugged into the phone jack, and it will send a network signal (that theoretically doesn't interfere with DSL or voice traffic) that the 2Wire knows how to recognize, and it should automatically handle the 2nd computer.
They apparently have a Mac driver: http://www.2wire.com/?p=266
Sounds like the cheapest option, if it works, but you may want to read through the documentation yourself. It's all online, and should be in your manual as well.
They apparently have a Mac driver: http://www.2wire.com/?p=266
Sounds like the cheapest option, if it works, but you may want to read through the documentation yourself. It's all online, and should be in your manual as well.