I just finished configuring dock #1 to be a PBX. The recently acquired Linksys PAP2T has 2 phone jacks, and each is configured as an extension in Asterisk. I used this link to configure it to use Sipgate (free incoming calls) as the incoming call provider. Google Voice is used for dialing out. It does this by calling the number that was dialed, then calling the configured incoming number (Sipgate) and connecting the two. All for the price of free. This isn't going to be our main landline since we already have MagicJack. Instead it's going to be used mainly as an in-house intercom system. So, now dock #1 runs Asterisk, Motion, bluetooth proximity and contact closure over IP.