My avatar is a drawing of me by Dominika from a trip to Peak Cavern (you can see the domeart.com logo at the bottom). It's at the Devil's Staircase (the end of the showcave), and captures me telling the freshers about the 'slide' (actually a mount for a film camera afaik). I chose it because I think it captures my likeness well, and I'm a big fan of her art.
The trip was a classic Peak Round, and Dome and a friend had joined us for artistic purposes. We were told not to wait around, so all the drawings were made on the fly, which I thought was quite impressive. It was quite a well documented trip actually, as I think this was the one where we ran into the Freems making their Peak Cavern films. As we went past a fresher tried to follow me up a muddy slope and slid bambi style back down in an excellent manner. The film crew were so pleased with this shot that they asked us if they could put it in the final film!
I think there's definitely a case for cave sketching becoming more common as it's much cheaper and less faff than photography. Only problem is that I suspect it's much harder to do decently...