Thank you all for your replies - this forum is overwhelmingly alive!
@gpathy I am using a wacom intuos 4 tablet (A5). I think it's haptically much closer to the "real" thing compared to the older versions. But the software part is nearly more important - I wouldn't have put much energy in the digital drawings if it hadn't been for manga studio. It's really much, much better for drawing than photoshop (or even painter)!
The layers can be limited to 1bit colour depth - which is imho the reason for the extremely short delay between the movement of the hand and the movement of the cursor.
@Robert T. I tried some drawing apps on my smartphone, but I think the wacom tablet is truly the better tool. Even the haptic has been improved (the surface is slightly rough, much closer to the feeling of pencil on paper).
@Urbanspinner hm ... sounds interesting. I've got no iPad, so I won't use this anytime soon, but the idea of simulating a cintiq-like tablet with the iPad is pretty tempting ...
My latest drawing is slightly olympically inspired (and perhaps a bit creepy)