This was a quick in-house piece I did for work. I think it was for the accounting department, who would understandably be relieved to see the end of tax season.
Drawn and typeset in InDesign. I've found it surprises people when I say I drew something in InDesign, which is normally used for typesetting and laying out books. InDesign has many of the same drawing tools that Illustrator has, so you can draw in it as well. No brush tool though, unfortunately. It can't do everything that Illustrator does, but if you need to make some simple art you can get by in it.
By the way, about the variable width lines in the guy's face-- there isn't any pressure sensitivity in InDesign like there is in Illustrator. So on a shape like the guy's ear it's not just one curved line-- it's actually a filled "C" shape. So they're fake variable lines (does that make any sense?).