Hi,
The pressure sensitive pen you have demonstrated is quite slick, and its simplicity and elegance shows a lot of thought.
I liked your Instructable as well. It seems Teachers makes great Salesmen as well.
Your pen can be distinguished from others on these points:
1. It is simple in concept with a linear assembly of components.
2. It is constructed from inexpensive and readily available components.
3. There are no unnecessary components, therefore saving cost, weight and labour.
I liked the soldering of the battery terminals to the wires (never thought of that...)
4. The fitting up between the IR LED and Tactile switch is original too.
One small detail I could suggest an improvement.
Perhaps you could spiral the wires around the tactile button shaft when soldering to the legs of the IR LED. This would put less strain on the wires and solder joints, and means it would be less likely to break from long-term use.
Anyhow, great work, and good to see the bar being raised.
Thanks.