xmodmap

The "i" key on my Thinkpad (Z60t) decided to die (even after cleaning). Fortunately, xmodmap to the rescue:

xmodmap -e 'keycode 76 = i I'

or placing it in ~/.Xmodmap

This maps F10 to the letter i.

I haven't solved the problem that capital I is only accessible with Caps Lock, and doesn't work with shift F10. Ubuntu Hardy Heron.