-mentioned topic-
My previous experience was sketching can be hardly covered in a small amount of time with inkscape.
But should it be?
Let's have a series of competitions on quick sketches, to prove it is totally possible!
To start off, I suggest the theme of the forest, and a wild animal, for example:

Hmm what should be the time limit, something short -maybe 15 minutes?
What do you think?
Look at the clock while drawing, and try not to go out of that limit.
The concept is similar to blenderartist forum's speed modelling contests.
Can you make some sketches of that image in fifteen minutes, and post it up here, so then we could choose the best looking sketch?
Some rules on the style: use black strokes only on a white background, and no filtering effects.
That way the technic shows up more.
Good luck, time for sketching!