YES, it is possible. I do it myself. I can access both ports simultaneously with no problem. Onboard e-net i use for cable modem, PCI e-net card (Farallon. Got it new on E-Bay - $15) I use for my home network including 3 other macs and a network inkjet printer. No college degree required.<br>
VicomSoft's 'Surf Doubler' software can be used to share your internet connection to another mac so you can surf with two computers at the same time.