If you are not satisfied with the T-Mobile G1 but would still like to enjoy the Google Android smartphone platform, it seems that you have a few more options. In fact, here's a video of an old HTC Touch running on Android. That's pretty cool and, by implication, it could almost mean that nearly any HTC Windows Mobile smartphone can be swapped out for some Google-y goodness.
In the video below, you'll see the Android OS running on the CDMA variant of the HTC Touch. You may know this specific handset as the HTC Vogue. In the video, you can see that Android is running pretty smoothly and because the OS doesn't come with integrated support for an on-screen keyboard (and since the Touch doesn't have a keypad), they had to create a custom on-screen keyboard so that the OS would be usable at all.
Interested in doing this to your own phone? The HTC Touch will need the MSM7X00 processor and you'll need to upgrade your radio to 3.42.50. Download the files, run the executable file included, and the rest is just gravy. Interestingly, a simple reboot will revert you back to Windows Mobile land