Use other lights as a caps lock indicator on newer thinkpads which no longer have a hardware caps lock indicator
Thinkcaps depends on the thinkpad-acpi driver and X11 (duh).
make
make install
Make install will copy the executable to /usr/local/sbin and set the setuid bit!
Then simply add it to your xinitrc file, or create a new one if you don't already have one:
echo "thinkcaps &" >> ~/.xinitrc