I think if you are concerned about keeping working, then Poser Pro is a must! The Queue Manager allows you to send a frame or movie(image sequence) off to the Render Queue Manager and continue working on your scene or another one in Poser Pro. To me this is the shiznitt!  Garee mentioned background rendering, which I think is handy for  doing some test rendering of lighting and such, Then I keep the Queue going with Image sequences or still renders WHILE I CONTINUE WORKING! its Awesome!
No more toe tapping and waiting around. I would pay $200 just for the Render Queue!
Time is money after all.