Ok, I'll be man enough to clarify my position, if Mr. Wizard up there agrees to offer some suggestions that use common sense and the context of the thread.

Sure, steel wool is abrasive to chrome. So is a cotton buffing wheel, if you attach it to an angle grinder and use as much pressure as you can apply for an extended period of time. In the context of this thread, we are talking about removing rust from chrome. If your chrome is rusty, more damage has already been done to it than you can do with a properly administered dose of 0000 steel wool and your lubricant of choice, such as chrome polish. Polish alone with a non-abrasive rag will likely never remove the rust, or at least not in a timely fashion. 0000 steel wool and chrome polish, applied with a light touch, will remove rust from chrome fairly quickly, and leave a very nice looking finish. It won't scratch if used correctly, at least not on a visible level. Is it doing something microscopically? Probably. I don't know, I don't own a microscope. Steel wool and chrome polish can make horrible looking chrome look almost new again, but it will not be new. It will probably need maintenance down the road, but it is a much more cost-effective option than re-chroming.

One point that was made that a lot of people don't understand is that chrome cannot be polished like other metals. Once a scratch is there you can't get rid of it. It is, however, a very durable surface and resists scratching under normal conditions.

If your chrome doesn't have any rust, there is no need to use steel wool on it, but if it is already rusted the steel wool will do more good than harm, if you use it correctly. Taking that into consideration, 0000 steel wool will not introduce any visible scratches to the chrome when used with a lubricant like chrome polish, windex, or WD40. 000, 00, 0, or anything more coarse probably will.

If you have a better way to remove rust from chrome and leave a presentable finish, without stripping and replating, I'd certainly like to hear it.