This map uses the beta version of Microsoft's Virtual Earth mapping system, so it doesn't always
work properly, and can be slow at times. However it does have some great high-detail aerial photographs.
Ignore the rather grainy ones a low zoom levels, and keep zooming in (use the + on-map control or double-click on a point of interest) until suddenly the poor quality images are replaced
by amazingly clear ones. You can even see the boats on the canal!
Another tip - this is actually a map of the entire world (well, the bits that Microsoft has photos of, at least).
Just keep dragging the image and you can go anywhere you want. Zoom right out for high-speed intercontinental travel (the mouse wheel works as a zoom control too).