Google Maps has now added a bunch of global cities to its roster. Some have more of a zoom than other, and a number of big cities are missing, so don't get your hopes up about seeing your house from space. Still, it's very cool to see cities such as Paris, Istanbul, Cairo, Beijing, Mexico City and Kabul up close and personal...
Ah! Melbourne! But it's a year or two out of date (Spencer St station is still uncovered). A useful addition would be time of photos (and a history feature would be cool, too! Maybe for the 'Enterprise' version??)
How can you forget Italy? :) Here's the Colosseum!
Even though there aren't that much high detail coverage (besides big european cities and places like iraq), it now gives same level of detail all over the world that it used to give only in US and that alone is a great improvement. Also i noted that the high detailed coverage has greatly grown in US, so i assume there are hopes for it to increase also in the rest of the world in the near future.
While most of the people are mainly intrested in seeing their homes from the space, google maps now also gives you a great resource for gathering some basic info (the kind of info you normally don't come to think of) about any country in the world (how much fo the land is farmed? how much is there mountains or other hardly inhabited areas? how big cities are there and how are they connected to each other? etc.).