Thanks for posting the driver!
I've tried a few things with adb, and so far I can't get an install to work over usb. I tried the following command.
C:\...\android-sdk-windows-1.0_r1\tools>adb install OperaMini.apk
579 KB/s (0 bytes in 278155.000s)
Had some basic info about the emulator, not sure what would be different for the G1.
The "adb shell" option allows you to access a shell on the phone over USB, which is really great but it appears you don't have root privileges. Any ideas on how to obtain root priveleges? Also, is there a command to install from the android shell? When i cd to /sbin i get access denied. I'm trying to figure out some kind of way to invoke an install either from the device or over USB.