Ducati tell us that you can now take a virtual tour of the fantastic museum at Borgo Panigale, after somehow squeezing the Google camera car up the stairs and round the tight corners and rooms. Ideal if you live nowhere near Italy and haven't managed to get there in person: http://goo.gl/maps/1wHaR
Sadly, and in grand Guzzi style, the Moto Guzzi museum has no such technologically advanced possibilities, and even the Guzzi website has only a simple page with one photo. Go there on Google maps street view and you'll arrive outside the faded and firmly-shut red gates on a glorious day, with only the ominous shadow of the ubiquitous Google camera car for company: http://goo.gl/maps/X74Bb
The Morbidelli Museum, in Pesaro, can only be arrived at via Google maps outside its entrance, ignoring its bland industrial estate surroundings: http://goo.gl/maps/0thBN
On the museum web page, there is what they call a virtual tour, but it's really a set of photos. The museum is very much worth visiting if you can.
The MV Agusta museum too has no virtual tour on the museum website at: http://www.museoagusta.it/home.html. It's worth going to, but in truth, there are more helicopter than motorcycle displays. Check out the entrance on Google maps here: http://goo.gl/maps/aEAcJ
Then, also in Pesaro, the MotoClub Benelli have put together their own collection of Benellis, though latest news is that it is shut due to lack of money. The entrance is hard to find, pointed out by a tiny white sign, off a busy road - Via Mameli 22, Pesaro: http://goo.gl/maps/DU8Ff
But there's no virtual tour, so there are some great photos of what's inside here: http://cbr250.com/forums/general-motorcycle-forum/9754-benelli-museum-pesaro-italy.html
If you're a Benelli fan, you can contribute to getting the museum back up and open, and the collection secured: http://www.officinebenelli.it