If you don't quite have the funds to buy one of the 3D printers currently on the market, you can make your own with Lego. Seriously.
Matthew Krueger (aka Mastermind on Instructables) made his LEGObot 3D printer out of various Lego bricks, a Lego Mindstorms NXT kit, and four power supplies, and it can print with either candy or glue gun sitcks. The downside? it can't make tall 3D-printed objects at present.
OK, the LEGObot is a little limited in what it can do, so it won't replace your regular 3D printer any time soon, but it can provide you with window stickers or candy sticks. Matthew hopes to test the printer with harder pine resin soon so it can make a wider range of creations. You can download the instructions on Matthew's Instructables page.