I wanted to get the media off of my htc hero and onto my macbookpro, but plugging the USB cable in does not result in a notification on android which allows me to mount sd card through the USB cable.
I found lots of promising articles, most of which pointed me to either Twisted, which didn't work for me, or to the Android developer SDK. I'm fully capable of using the SDK but this seems like overkill for such a simple issue.
My Solution: Close the lid on the macbook. Plug in the phone and then I get the notification allowing me to mount a USB. Once mounted, its the same as working with any other USB card.