Troika's Liliput Construction very small but perfectly formed pen is a ruler (OK, a short one), a stylus, a slotted screwdriver, a Phillips screwdriver and a ballpoint pen.
Doodle on your iPad with the stylus without it feeling like you're finger-painting.
Twist the front section to retract the refill when not being used for writing. This section also pulls out of the pen to facilitate refilling when necessary.
As the barrel is made from brass, the pen has a reassuring weight to it as well as being nigh on indestructible!
The hexagonal barrel won't roll away when not in use and is comfortable to hold when writing.