Really, there is no need for this post… because Cupcake (an updated version of Android found on the HTC Magic and ported over to the G1) is quite friendly to users without data service. The ability to skip activation allows the user to delay activation until the WiFi connection can be initialized. And since rooting is required, the modified recovery image and engineering SPL makes backup-and-restore trivial.
What are the options?
As of now, there are three major builds containing this Android version. Haykuro maintains two series, the ‘G’ builds sourced from Google and the ‘H’ builds sourced from HTC for the Chunghwa phone. TheDudeOfLife maintains an analogous ‘G’ series. So far, there is no way to say which series is universally “better,” since each has its perks and quirks. So I would recommend trying them all if the time is available, since formatting is necessary anyway.
Where to get this Cupcake stuff?
Both Haykuro and TheDudeOfLife use Google Code to keep track of their progress:
They also post regularly at the xda-developers forum.
How to apply the update?
Haykuro has a nice guide written up. I found it quite helpful, but here’s some of my own commentary. Keep in mind that root access (specifically, the modified recovery image) is required. Haykuro’s guide covers that too, I believe.
For the adventurous (who isn’t who has performed this update?), funbacon has posted several enhancements.