I bought the Motorola Bionic and what I did was wipe out the Eris and flashed Macdroids. I let my girlfriend use it to play games. It will only have internet access by wifi but you can still have your google account on it and use the market to download games/apps for it. One thing I did was to not allow it to sync my Google data to it (contacts and so forth) I deactivated those features.
If you login to the market from your computer you can still send apps to it, when you pick an app it will ask which device to send it to. (both my Eris & Bionic show up on the choices)
I also rooted my Bionic so I also have wifi tether in case the Eris needs internet on the go
Mike
