More firmware tricks
Though this isn't for a Canon DSLR, this is a new development in firmware hacking for Canon DIGIC-II-based cameras. The CHDK Firmware allows you do add some extended features to your Canon PowerShot A610, A620, A630, A640, A700, A710 IS, S2 IS and the S3 IS cameras.
Like with any firmware, there are some risks involved, but if you have one kicking around, you might actually get real use out of that 'Direct Print' button with things like:
Scripting! =>some examples
RGB Histogram
RAW images
HDR
Unlimited DOF
HDR Mosaic
Timelapse movies
Games?