I attended the All Arizona Messier Marathon last weekend. My goal was to sketch all 110 objects in one night. I wasn't able to get them all, but I did manage to sketch 104.
The full report can be found here: 2009 All Arizona Messier Marathon
It's definitely a different kind of sketching experience. I printed my templates on 90# Index paper so they'd hold up to a lot of shuffling, dropping, wind and the slim potential for dew. I planned to work small: 1.5" diameter circles, and that allowed me to fit 20 drawings per page. I worked with an HB pencil, blending stump, clipboard and my red Frankenlight.
I like to plot as many stars as I can, so I really had to hold back if I wanted to have any chance at completing the marathon. Over the course of the night, I would have to average about 5 minutes per object--including starhopping and sketching. The open clusters in the Winter Milky Way were the hardest to ration. The Spring Galaxies, especially the Virgo Cluster with their sparse star fields and close proximity to each other were the best part of the run.
Poor planning and morning clouds withheld six of the objects from my grasp, but I can say it's definitely possible to sketch all 110 overnight -- if you can find them all. I'll be giving it another try during the next favorable marathon.
Here are the sketch sheets...