threed.io is a browser based tool to generate custom device mockups on the fly. Upload your Designs, make adjustments and download your custom mockup! Even works pretty nice on mobile. We're still in beta, but if you're interested in threed, please read the about text on the site.
If you're ever looking for product mockups using nice looking 3d device placements, then this should be on your list. Especially considering it's free, unlike many other options out there.
Threed looks great, probably going to use it for Dribbble shots!
I can see the potential in this tool however it needs a few tweaks before it becomes something I can use. I would love to have more control on the glare such as a sliding scale rather than just 'on' or 'off' (both of which don't look realistic enough).
Keep going, it's a great idea :)