PhotoStamper is a simple application which will add a date/time stamp to your jpeg photos. You can decide which corner of the photo to put the stamp in, as well as configuring the font size. It currently uses the last modified date of the file as the timestamp.
I wrote this after finding that most of the other tools to add date/time stamps were not free. It is written using Java 1.5 (Java 5.0) so you'll need a Java runtime 1.5+ on your computer to use it.
The tool won't overwrite the original file - it wil save the stamped file to <originalfile>_stamped.jpg.
Usagejava -jar PhotoStamper.jar [options]
Stamps the last modified date onto the image file. PhotoStamper file [-s size] [-x xoffset] [-y yoffset] [-a anchor] [-c color] file File or directory to be stampped. -s Font size in pixels. -a Anchor for text. One of tl, bl, tr, br. (top left, bottom left, etc). -x x offset from the anchor. -y y offset from the anchor. -c color consisting of r:g:b values. 0-255. e.g. PhotoStamper photo.jpg -s 50 -x 25 -y 25 -a tl -c 255:0:0
Unlike some of the commercial tools this photo stamer will result in a small reduction in image quality as the whole jpeg will be recompressed after the date/time stamp is applied. The difference with the original is very small so you probably won't even notice.