I bought a really basic Wacom Bamboo Pen and tablet yesterday and I've been on it almost constantly. It is amazing although a little frustration. Getting the initial control doesn't take too long but the hand-eye co-ord stuff takes a bit of time. Not a single peice of paper or drop of ink was used.
This sketch is a robot I did as a trial. It seems to link in well with GIMP and it is easy to do some great looking work. I want to do comic and illustration type cartoon work like Ingi's here. But doing the painting stuff illustrations are great fun and really fulfilling.