Seeing The Last Supper on the Web
Before you go, you should have a little information on the church the Last Supper is in, and some information on the work itself. Arounder Milano has this information, and has a very detailed scan of The Last Supper available online. See The Last Supper by Leonardo da Vinci.
Now the the Last Supper can be viewed online at 16 billion pixels by Italian imaging firm HAL9000. You can really get a close look, zooming in on key details you'd like to see. Note: it may take some time to load.
Buying Tickets for The Last Supper
The debut of the Da Vinci Code movie will bring out the conspiracy seekers in droves, so order your tickets for this summer as soon as you can. Only 20-25 people can see the work at one time, for a maximum of 15 minutes. Only if people don't show up will you be able to stand in line and hope to get a ticket.
We recommend Select Italy for ordering your Last Supper tickets online. Try to aim for three months advance purchase. For details: Museum Tickets for The Last Supper - "Il Cenacolo" Milan Italy.
There is a surcharge getting tickets mailed to you in the US, of course. If you would like to try to order tickets from the source, over the phone to Italy, here is the information from Cenacolo Vinciano.
And lastly, if you have a hotel already, you might contact them and see if they can get you tickets.

