A couple months ago on Digg, there was a post about putting a Mont Blanc refill in a Pilot G2 case. Some of the comments indicated that the G2 itself was a very good pen. So the last time I went to Wal-Mart, I tried out the G2, which is a gel ink pen. Unfortunately, it was not designed for left-handed writers. The ink takes way too long to dry, and if you attempted to write with it, you would end up with a page full of smudged ink. If you're one of those lefties who gives us a bad name by turning the paper perpendicular or even upside-down, perhaps you could make it work, but I'm not familiar enough with the acrobatics of that method of writing.
I must recommend that the left-handed stick with Pilot's Extra Fine (0.5) VBall Grip, the ink of which dries quickly enough to cause only the occasional gentle smudge.
On a related note, Mead sells left-handed notebooks which are just regular notebooks with the front and back covers swapped so it opens on left and you write on the page on the left with the spiral on the right. Although I'm a bit ashamed that it took seeing one of these notebooks to come up with the solution to spiral hand, I now open all of my notebooks from the "back" and write on the left page.
The state is that great fiction by which everyone tries to live at the expense of everyone else. - Frederic Bastiat