Bridging the Gap

While travelling home, it's nearly impossible to dig out the easel from under the suitcases to do a painting. 
And taking time out from the trip can cost money in extra hotel bills.  So, how do you keep your hand and eye ready when bridging the gap between locations?

I found myself in a restaurant which covered their tablecloths with paper.  My hand was itching, so I took out a pen and started to draw.  Suddenly there was a beach with driftwood, a dog and a schooner out on the waves.  The only drawback is that your waitress may be reluctant to put your plate down on your tablescape masterpiece!