I just came across this while browsing online hobby stores. It is a precision hobby knife with a ceramic blade. It is $6.99 without shipping. Hopefully, I can help somebody save a few $$ on hobby blades.
http://www.safetyknivesandcutters.com/p-151-precision-cutter.aspx

I've seen these at Michael'a, Hobby Lobby, and I think even Wal-Mart. From what I can tell through the packaging, it looks like they would be more suited for think plastic sheet or parts, and removing mold lines and such, since the "blade" seems quite small.
I think I'll get one soon just to see how well it work...it would be another tool!

I have one of these. It's more akin to a stencil cutter.

The blade is only about 1.5mm long. Suitable for cutting out complex shapes in paper or very thin sheet, but not much use as a hobby knife.

Well, that sucks. Thought I had happened upon a treasure. I'll probably still get one for scribing and the odd bit of flash and mold lines. Like majjanelson, another tool.

Ceramic blades are great for linear cuts (ie. along the blade), but they have little lateral (shear) strength and I would be hesitant to use it as a seam scraper where most of the action would be across the edge of the blade rather than along it.

Well then. I guess I will religate it to my scratchbuilding tools.