nanowrimo_lj | Mapping Programs for Macintosh

So, I'm realizing now, it would be a good idea to have a map of the world my novel takes place in. But, I'm an awful artist, only barely competent on a computer and I own a Mac. Also, I'm a broke student.

Does anybody know of any freeware or shareware or, heck, even demos, of map-making programs for the Mac? I've been tearing apart every search engine I can think of and so far, all I've found is a couple of vector drawing programs.

Thanks in advance!