[geeks] open source (or at least inexpensive) replacement for Surfer

[ericj]

Hi,

I've been doing some contracting lately that involves using Golden
Software Surfer. It's a pretty cool package that I know how to work
with, but my only Windows machine is my laptop and I'm tired of having
to use it (and don't feel like dual-booting or digging for an old,
buried Windows XP DVD). Does anyone here know of a nice piece of mapping
software? 

I don't need all of Surfer's abilities; I only:

1) Grid incoming data from an Excel file
2) Create a 2d contour map of the grid file (custom colors and contour
lines)
3) Export the output to a jpeg (after blanking the spots where the
gridding routines create bogus data due to extrapolation beyond the
edges of the data).

I'd prefer something under Linux, but anything running on x86 free OS
would be good enough.

I tried some quick Google, but didn't see anything terribly promising in
the first couple of pages.

--

"Facts are the enemy of truth." -- Don Quixote

Eric Johnson