Stephen Masraum

Actually high quality stainless can rust depending upon what it's for. Without being a materials or metallurgical engineer I guess the difference between high-carbon and stainless steel is (very basically) the amount of carbon and chromium. The more carbon and less chromium the softer it will be and the less likely to rust and vica versa. I have some really high quality knives made by Benchmade which are in the middle ground so they are stainless but for extra hardness so they hold an edge longer they are at the minimum amount of chromium to be considered "stainless" and so if not cared for properly they will rust.
Sorry for the tangent folks

Paul H

Not that many people will care but since someone asked:

Stephen is correct, there are a wide variety of stainnless steels, with varying properties (hardness, rust resistance, price etc) dependant on the chromium/carbon/nickel composition. Type 302 is the most common stainless, it resists corrosion and oxidation (this is countertop/stove type 'good' stainless). 400 series stainless is the cheap stuff (without nickel) typical use is mufflers.

I think the 300 series tend to be non-magnetic, 400 series is generally magnetic.