(Updated: July 13, 2013 with high resolution photos)
On June 29, 2006, my friends and I visited the Ghibli Museum. The museum (aka. Mitaka's Forest Ghibli Art Museum) is located in the suburbs of Tokyo. It is about 15 minutes by train on the JR Chuo Line (aka "Suicide Line", the line alignment is almost totally straight) from Shinjuku Station.
Unfortunately, you are NOT allowed to take pictures inside the museum, only outside, so that is what I have.
Also you can't just show up and buy tickets at the museum, if you are in Japan, you need to buy your tickets in advance from a Lawsons convenience store using their electronic ticket machine. If visiting from overseas you could either buy them from overseas (check official website) or if you know Japanese or some Japanese or if you are able to copy the name of the Ghibli Museum onto a piece of paper, you could go to the Lawsons convenience store and ask a clerk (using a lot of hand gestures?) that you want tickets to this museum. But be warned, the museum is kind of popular and may be fully booked a week in advance.