I use the Griffin stylus and although it does the job well enough it's a long way removed from using a pen on a tablet - I find the soft nib makes it difficult to write accurately. The other pens I've seen all seem to have a similar design - presumably to make the nib appear to the iPad as a finger.
I understand pressure sensitivity isn't going to be an option but a relatively hard nib would make it a lot easier to 'write' on the iPad.
