Check it out: http://www.googleartproject.com/c/faq
In the site, there's various ways to move around; you can look at the gallery layout, then click the room you'd like to go to, and voila, there you are - in virtual reality looking at the paintings. You can move up close to each painting, and are able to zoom in extremely close to many of them to check out the brushstrokes. There are various drop down menus; to choose a gallery, to choose a painting, to choose an artist, and there's also information on the paintings, or you can search for other paintings by the same artist and see which galleries hold them. So far, 17 galleries worldwide are involved with the aim to cover as many as possible. Its early days yet, but so far its looking very impressive.