I just got some Uniball Signo bit pens from Jet Pens. Jet Pens is a great place to get cool pens that are hard to find in the United States, like the Pilot Hi-Tec C. The Uniball Signo bit is touted as being the “World’s thinnest pen.” I like writing with a very fine pen, and this one is easily the thinnest I’ve ever seen. Almost like writing with a very sharp pencil, the tiny tip can seem to be scratching against smooth Moleskine paper until you get the right touch. The lines from my 0.38′s look downright chunky and bold in comparison with the 0.18mm lines from these.
If you’re a fine point fan, you need to give them a look. They’re not cheap, though, so be sure you mean it.