I would second the utility of SURFER. As already mentioned, it's from
Golden Software in Colorado--they have a toll free number 800 972 1021
and a regular number 303 279 1021. There's a Windows version out now
(approx. $400) that we just bought which is working pretty well for us
(and you can make things look soooo pretty). We've been producing
contour maps of a site and also 3d surface maps. You can also use it
for artifact distribution maps etc. We've also been importing the 3d maps
into autocad.
--Christine Flaherty