Google have been kind enough to provide free Android devices to Android developers who meet their selection criteria. The criteria being 3.5 star or higher rating and more than 5,000 unique downloads. I received my email from Google on March 4th, with the actual device arriving on 24th which is great service for a free product.
While most developers already have a device you can never have to many. It is always useful to have a couple of devices running different OS versions as well as different screen resolutions. The emulator will only get you so far, being able to test your application on a variety of devices is always the best option.
I was lucky enough to receive a Nexus One (very glad because I already have a Droid). Below are a few pictures from when my device arrived.
This is a great good will gesture by Google towards developers. Thank you very much Google.