On this page, there is a clearly explained and easy to use demonstration of displaying a Yahoo map on a web page. Not only can you display a map on the page, but you can add points, center to a particular location, or add an overlay of many points to the map.
I'm quite sure there are other tools from Google that do the same thing, but this struck me as VERY easy to use, and implement.
And like most of the time, I like to post these kinds of links on here so that I can get to them someday :)
Here is a link to the JS-Flash API Guide for Yahoo Maps
This is my first try. (and fyi, it took all of about 5 minutes)