I was really gutted that I didn't get to see the Da Vinci exhibition at the Victoria and Albert museum – it would have been great to actually see the great mans works.
Well if you've got Vista try this - http://www.bl.uk/ - it's the next best thing.
(You can get directly to the turning page app at http://ttpdownload.bl.uk/browserapp.xbap)
Not only do you get to have a look at the Arundel and Leicester Codex – you can also look at the Lindisfarne Gospels, Mozarts musical diary and host of other books.
Not quite as good as actually seeing the real books but it's got to be the next best thing.