Basically I'm looking for something that would easily enable me to display a world map onscreen (most likely would consume the entire size of the window, not that this should matter) and get pixel based coordinates for certain real-world coordinates, which would then be used to visualize some data periodically obtained from the server (with pretty jQuery aided animations).
Bonus points if this allowed me to supply my own map image, maybe even in SVG. I realize this image would need to meet very strict criteria for the coordinates to "match up" and this would probably mean that I'd just need to code it myself, but meh, who knows.