Check out Rob‘s DIY 555-based remote timer for Canon SLRs! He says:
Canon makes a SLR camera remote timer that sells for a couple hundred dollars. Using inspiration from various web sites I built one for myself using about $15 worth of parts from RadioShack.
First, it is a simple wired camera remote control. Just plug the cable into the remote jack on the Canon SLR camera and the black button on top will trigger the camera auto focus, while the red button will focus then take a picture.
Second, it is a timer than can be used for time lapse photography…
Continue reading the plans at his blog, My Name Is Rob.
Via MAKE Blog