Hi Lorna, sounds good. Here are some suggestions:

* tail -f
* file
* locate
* which, type
* pushd, popd, dirs
* wget, and its -S option for seeing the HTTP headers
* convert (and ImageMagick in general)
* poster
* dict, look
* killall, xkill
* dc (or bc if you insist)
* units
* diff -u