the iPhone and iPod Touch stylus is your finger. Then you never lose it....
My problem with that is one of fine control. With a "traditional" stylus, I can control images down to a pixel or so in size- great for fine work.
OTOH, the size of the "tip" the stylus controls is variable in size, so I suppose its possible that the tip size is variable with devices that use only fingers for control.
Do you know if it has that capability?