A macro lens can cost hundred of dollars, which you can save if you're handy with a soldering iron and aren't afraid to operate on the lens that came with your SLR camera. Even if you aren't, though, this DIY video is one of the most compelling and cinematic ones we've ever seen, so it's worth a look.
Vimeo user Lozzless takes a less expensive 18-55mm lens and turns it into a macro lens using a few common workshop tools and a floppy 7pin cable. He modifies the lens to remove the autofocus, solder on the cable's wires, and otherwise transform the lens.
Whether you have the time or inclination to attempt this project or would prefer to use a cheaper pair of binoculars to make a macro lens or just use a pair of cheap reading glasses as a macro lens, it's an amazing video - kind of like watching someone perform surgery.