The G1 is extremely versatile, I have been able to use it for a lot of things I would normally turn on my laptop to do. I just loaded my phone up a week ago with several old school NES games.
While I was playing Super Mario Brothers I thought about you. I had to share it, all the cool kids are doing it. You can play Super Mario Brothers 1, 2 and 3 and even Tetris (bonus!). I even have Dr. Mario to play, which is a lot like Tetris.
You can get the Nestoid app from the market but I can’t tell you where to get the .rom files (but Google is your friend) but if you like classic Nintendo games you should download the app and investigate getting some .rom files to play. My husband told me I can even use game genie codes if I want.
For me, being able to play the few games like Super Mario Brothers and Duck Hunt from childhood that I would play back then is a very cool feature. I’ll take a screenshot of it tonight and share it on Twitter, or maybe do a video for you real soon. 
Now if T-Mobile would only allow tethering…
*update: I have found an excellent tethering app, details can be found here
