This what computers are good for — creating useless but entertaining programs that replicate stuff that worked just fine in the real world. DK of Mediasnackers tweeted a link to this awesomely useless and free Mac application called "Poladroid."
Poladroid puts a cute Polaroid on your desktop that you can drop any image file on. With that characteristic "bzzzzt" sound, it creates a "polaroid" on your desktop that slowly develops. You are welcome to shake it, but I’m not sure it does anything. After a minute or so, your polaroid is revealled in all its sepia-toned, oversaturated glory, which you can then save onto your computer for future posterity.
Head over to the website to make your own polaroids. Drop few bucks in the tip jar if you like, or just leave a nice comment to the developer (get it!), Fuzina.net.