A simple screen grabber. Immediate or delayed grabs.
Win32 version saves to BMP format image files. Download winsnap-1.0.tar.gz (source and executable). When I needed a screen grabber I had a hunt around the net and the smallest "basic" grab utility I could find was over 0.5Mb. winsnap clocks in at 8192 bytes.
Cygwin version saves to PPM format image files, or uses ImageMagick convert utility if installed. Download cygsnap-1.1.tar.gz and read the README for more info.