Andrew Saur and Angel Sarkela-Saur paint with coffee, using it as a basis for watercolors. It's pretty cool stuff and definitely a medium that we can get behind. That's part of a self-portrait of Andrew there, which sort of reminds me of me before my caffeine tolerance level became ridiculous.
I admire their restraint. Around here, we'd have finished off the pot before you could even get a brush ready.