Na Young got me a great birthday present this year. It's called the Alu Pen and it's a stylus for the iPhone or the iPad. Now I've used a stylus on my computer before in the form of a wacom tablet. But the Alu Pen is a bit different. The iPad and iPhone are capitative touch devices which means that they don't rely on pressure sensitivity but on the electrical signal that flows through a person's finger. The Alu Pen is then at a disadvantage when it comes to drawing and painting on the iPad. There is no pressure sensitivity to bay the width of the pen or paintbrush. This is a hindrance but it can be overcome on a limited basis. It works alot better on painting than drawing, in my opinion.
Where the Alu Pen shines is in it's ability to interface with a tablet device. Previously, If you wanted to do a drawing and render it directly on screen, you would have to shell out at least $1000.00 for a wacom cintiqu tablet. I know, I bought one about a year ago. It was a cool device but there were a few issues such as a less than stellar screen and the fact that it was always tied to a computer. These two issues are completely solved with the ultra portable iPad.
So I paid about $700.00 for the iPad and the Alu Pen was about $30.00. What a deal!
The programs that really shine with the Alu Pen are Penultimate and ArtRage. I use Penultimate to sketch out ideas and ArtRage to paint. I would really recommend this stylus for the artist who has an iPad. It is limited and doesn't have the ability to vary pressure but maybe this can be addressed in the software in the future as the hardware is limited.