I need to create a map application that highlights various hot spots around the globe. Google Maps would be ideal since my only issue with it is that it’s so universal, it can tend to look a bit generic. I’d therefore like to spice it up a bit with my own graphics. I’m wondering if there are ways to skin it (or some cool libraries)?
Campaign Monitor (see attached image) has a nice implementation. It’s powered by Google Maps but the map itself and the icons look bespoke (I could be wrong).

The CampaignMonitor.com example you post (their Worldview feature) is indeed done with Google Maps. Apart from diving into the Google Maps V3 API itself, here’s also a tutorial for “Embellishing Your Google Map with CSS3 and jQuery” which should go into a little more depth with regards to the API and how to manipulate it to use your own custom graphics.