Disclaimer: What you do with your phone is on YOU. This type of stuff can turn your device into an expensive paper-weight. It's also a violation of this and that. I'm providing this information for educational purposes, etc. (I'm going to have to insert this type of thing into the beginning of a bunch of posts, aren't I?)
So, I rooted my G1. I've been putting it off because I was afraid hacking might cause some problems that would inhibit my reviews or give me a different experience than the majority of you. So far, the opposite has turned out to be true.
Before modding, I had two major issues that drove me crazy. The first - and most troublesome in terms of interrupting my work - was that I couldn't see a lot of apps in the Market that were available to the rest of you. I wanted to upgrade Power Manager to pro, but when I clicked the update button, I was informed that the program was not found in the Market. This happened every day, with dozens of apps. It didn't matter if I followed a QR link from a website, a notification in aTrack Dog, or a prompt from the Android Market's own version-checker.
I spent some time trying to chase this down, but it didn't seem like an acknowledged problem. Users popped up here and there complaining of one or two missing apps, and those offering support looked at the problem on a per-app basis. I never saw anyone saying that they were missing out on all of the most exciting new releases. But I probably spend a lot more time in the Market than the average user.
I gave up on the second issue long ago. Importing contacts from my SIM and sometimes even adding a new contact resulted in a force close of my contact book. The exact errors changed, but the behavior was the same. Most of the time, I could not save a new number to my phone - even after a factory wipe. I stuck with the short-list that I was able to add, and forgot about it.
After a few hours of reading, rebooting, transferring files, etc. I now have a rooted G1. Both the missing app and borked contact list problems have been repaired. Wow, I forgot how many people I know. The downside to this is that I wasn't able to purchase the pro versions of the Market's back-up apps first. It doesn't make that much of a difference though, because to make a complete backup of your G1, you need root access.
I've lost my contact photo associations and apps and all of that stuff. But it's O.K. The first thing I'll do after rearranging the phone to my tastes is to make a backup image of the. whole. entire. phone. state. Thank you, xda-developers, Android-DLs.com, and all of the brilliant people working on this stuff.
My Android gripes are gone and I'm looking at some nice new possibilities: multi-touch, screenshots, device back-ups, tethering, and loads of other goodies. I'm glad I waited. There's actually an app for auto-upgrading the modded OS now. I haven't been on long enough to use it yet, but... wow.