I played around with the EXIF tagger script tonight. Its nicely done but ... for tomari's application, I'm not too sure how to get a usable script working. The problem is, when he wants to "tag" a photo, the following steps would be necessary with any script :
1) Press the <ALT> key (or key sequence) to enter ALT mode.
2) Press the shutter button to launch the script
3) The script sets itself as ready for the next picture - puts the "!" symbol on the LCD and exits <ALT> mode.
4) Take the picture
5) Press the <ALT> key (or key sequence) again to enter ALT mode.
6) Press the shutter button to launch the script
7) The script "tags" the EXIF of the most recently taken picture, removes the "!" symbol from the LCD and then exits <ALT> mode.
Lots of key strokes to get a simple result.
However, if you just want to have a script running all the time, the shutter button becomes unusable during that time. You could use another key to trigger a picture under script control or a USB remote switch. Using that method, you avoid all the going in and out of <ALT> mode stuff shown above.
Is this any easier ?