Roman Nurik, an Android engineer, recently gave the Android Asset Studio an awesome new tool that allows users to create gorgeous, high-res PNG images of any screenshot framed by actual press asset photos of Android devices.
The resulting images are, well, pretty. Gone are the days when developers or designers have to spend time in Photoshop layering up images and fabricating gloss, just to get an appealing graphic to show an app in action. Heck, even if you aren't a developer, this tool is still fun to play around with.
At the moment the selection of device frames is limited to the Nexus One, Nexus S, and Motorola Xoom, but it sounds as though more devices will be coming soon.
The tool only officially supports Chrome right now, but I've had luck right-clicking the output image and "Saving As" in Firefox as well. At any rate, if you're interested, head over to the Android Asset Studio and give the tool a go.