I remain logged on to both Google Talk and AIM throughout the day using Adium in my office b/c I use it to communicate with colleagues and friends. Is there a way to also remain logged on to those services on JiveTalk but not have the IMs go to my phone when I am also logged in on my computer? I basically only want the IMs going to my phone when I log off from my computer in the office. Is this possible? Thanks.

nope, not possible. Its the way IM services work. server directs the message to whatever client you are connected from. So if you are connected from 2 places it will send the message to 2 places.