Yes, if you can keep at it when your hand feels like it's about to fall off. ;) It's probably not so smooth as a proper airbrush, and you have to colour in lots of small, short strokes as you don't have a continuous airflow (just a lot of little "puffs"), but you can get a nice effect with it.

I haven't tried the Letraset one, yet, as I haven't gone and got a can of air yet, but soon, preciousss, soooon...