The newest addition to the Android Marketplace is a free Adobe Reader app. It looks good, but keep in mind that it requires Android 2.1 or above and is currently only supported on some Android devices:
Currently Supported Devices: Motorola Droid, Motorola Milestone & Google Nexus One (While we have not yet tested against other Android devices, we expect they may also run the application just fine.)
If you've got one of those devices or want to risk trying out the app anyway, here's what you'll get:
Adobe Reader for Android offers multi-touch gestures, like pinch-and-zoom, as well as double-tap-zoom, flick-scrolling and panning. We've also added a "reflow" mode, which will take text-heavy documents with wide margins, and automatically wrap the content for easy viewing on smaller screens.
Check out the Android Marketplace to download the app. [Adobe]