It's heartbreaking... Android 1.5 doesn't support any bluetooth profiles other than the standard headset. Data transfer and (I assume) all other neat tricks you want to do is supported by Android 2.0, which the Eris will receive in the "first quarter" next year. If I'm not mistaken, the only Android devices that do what you want are the Moto Droid, and phones that have been rooted.
I was very sad to learn this. I figured an OS as open as Android would support unrestrained bluetooth functionality. But on the bright side, it's actually best for me to plug in my phone via the USB cable, because it keeps my battery from failing by the end of the day.