Linux on Nokia Phones

Okay, i've spent some time on TuxMobil and other sites, reading up on Linux for mobile phones... and it's mostly connectivity issues between Linux Distros and Mobile phones. My question is though, that since i've seen so many recent launches (especially from Motorola) with Linux-Based PHONES, is there a way to reflash my nokia e60 with Linux? And make a backup copy so i can restore Symbian 3.x.x, in the event that i want to make the move back? I haven't been able to find anything about it. Anyone have any suggestions?