John Paul Caponigro has a short but informative article on doing color to B&W conversions with (the oft abused and misused) Photoshop in Dec. 2004 Outdoor Photographer. Not my favorite mag by any means (in fact the first issue I've ever purchased), but this article is worth reading. I don't use PS, but the techniques can be coverted for use with, or approximated in Picture Window and The GIMP, both of which I do use. (In a very restrained and tasteful fashion, of course.)

Lee (abuser of parenthetical remarks)