I got approval to go ahead and work on connecting our existing PBX at work with an asterisk server. So...I ordered up another T1/E1card for the PBX and a T1/E1 PCI card for my asterisk server. The two systems will be cross-connected by an E1  crossover cable, essentially giving me the ability to have 29 simultaneous conversations routing between the two systems. It should be quite a fun project, and in the end should save the company a healthy chunk of money. Our hope is to use the additional VoIP extentions for our employees out in the Vancouver office, as well as travelling users.
 E1 is a protocol similar to T1, only it has 30 channels versus T1's 24. In my case, it's going to be an E1 PRI, which allows 29 channels plus 1 channel for signalling, CID information, etc.