[drifkin]

I'm also left handed and have tried out way too many pens. As others have suggested, Uniball Jetstream pens are fantastic and are nearly impossible to smudge by accident. They also come in a variety of sizes. I really like the 0.38mm for taking notes on the small margins of academic papers.

The main pens I've been using these days are disposable fountain pens [1]. They write great and somehow the ink rarely smudges, though more often than with the Jetstreams. But overall I find it more pleasant to write with fountain pens.

[1] http://pilotpen.us/brands/varsity/varsity/