Mapping many addresses on a USA map

I'm looking for some points as to how to do a fun thing. I have a database of my customers

that include their addresses and I'd like to create a map of USA (and Canada :) with a dot on

the map representing each customer. Is it doable with any webservice such as MapPoints

or something similar ? Thanks in advance !

Here's an intro article here:
http://www.mp2kmag.com/a103--chandu.thota.net.framework.mappoint.html
And a more detailed article here:
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/mappointsdk/html/mpn35devRenderMapsWeb.asp

Thanks DN, any pointers for a free service ? Since this is a "out of curiosity project" for me I'm not really willing to pay MS for the Webservice.
Oh right. Not sure of any free ones.