(First attempt, so excuse any faux pas)

I'm trying to find either a package or toolkit to map a large 
volume of data points. 
I'm not sure of the final metaphor, but the one of interest just now
is laying down a "map" (e.g. Streets), and then plotting the data as 
points within the map, showing "hot" where the value (or count) is
high,
and "cold" where the value/count is low.
What would help is the ability to plug this on to a database & show a
series of plots (per date for example), but I can take care of that if
needed, I just want to avoid heavy graphic programming if possible.
TIA

Hi elipsis,

There are a multitude of data visualization tools available, I've
assembled a list of tools for you to look over - the best way to
determine which is right for your needs is to "kick the tires", as it
were, and try the demos available.

3D Active Chart might be right up your alley.  The page says it can
import data from any ODBC source, and the accompanying pictures look
like the program would lend itself well to a "thermal map" (there is
even a 30 day free trial available):

3D Active Chart
http://www.rinvoice.com/activechart.htm

IRIS Explorer also seems to fit the bill, and offers a free trial as
well:

IRIS Explorer
http://www.nag.com/Welcome_IEC.html

Penn State University's Astronomy Department has a large list of data
visualization resources, many of which are free, in the public domain:

Visualization tools 
http://www.astro.psu.edu/statcodes/sc_visual.html

ThinkAnalytics also has a rather exhaustive list of tools to try,
including a Freeware section at the bottom of the page:

Software for Visualization
http://www.kdnuggets.com/software/visualization.html

For other products, and articles discussing various methods of data
visualization, have a look at the Open Directory's listing:

Information Visualization
http://dmoz.org/Reference/Knowledge_Management/Knowledge_Discovery/Information_Visualization/

I hope these help you with your project!

Good luck!

missy-ga

If your data is based on a map, you might consider a GIS package, in
particular, GRASS.

"GRASS GIS (Geographic Resources Analysis Support System) is an open
source, free software Geographical Information System (GIS) with
raster, topological vector, image processing, and graphics production
functionality that operates on various platforms through a graphical
user interface and shell in X-Windows. It is released under GNU
General Public License (GPL)."
http://www3.baylor.edu/grass/index2.html
Windows port to NT and 2000 Pro
http://www3.baylor.edu/grass/5.0winport.info.html