Here are some basic facts on the Paris Museum Pass:

Duration and Costs:

• 2 Days:  39 euro
• 4 Days: 54 euros
• 6 Days: 69 euros

Use is for consecutive days.  For instance, if the start date for using the 4 day pass is Monday, it can be used Monday, Tuesday, Wednesday, and Thursday.   If it is not used on Wednesday for example, it is still counted as a day of use.   The duration of the pass starts on the first day of use, not the date of purchase.

Monuments and Attractions:

Over 60 good monuments and attractions are included.   Here is the list: http://en.parismuseumpass.com/rub-museums-monuments-by-name-5.htm

Where to Buy It

• Airport:  Look for the Orange Tourist Information desks.
• Museums:  The Paris Museum Pass may be purchased at all participating museums and attractions.  However, the travelers will need to wait on the regular line to buy.  So, if purchasing at a museum or attraction, it is best to go to a lesser-attended attraction as opposed to a museum that always has long lines.
• Tourist Centers:  In various parts of Paris there are tourist centers where the pass may be purchased.  For locations see: http://en.parismuseumpass.com/rub-the-pass-points-of-sale-3.htm?cat=1&type=31

Other Benefits

• I find by having the Paris Museum Pass (as well as those who travel on my small group tours to Paris) is that we tend to go into places or attractions we would not normally go into if we had to pay out of our pockets.
• Need a bathroom real quick?  Most museums have clean restrooms.  With access to over 60 places scattered all over the city, a clean bathroom is nearby.

Is It Worth It?

Just for the consideration that there is no waiting in line makes the pass worth it to me.   When taking into account admission costs to museums like the Louvre (10 euro), Versailles (18 euro), Orsay (9 euro), and Arc de Triomphe (9.5 euro) it looks like it makes economic sense too.

Also Note

• The Eiffel Tower is not included on the Paris Museum Pass
• Even though the Paris Museum Pass offers no-wait-in-line VIP admission, there are  a few places (i.e,. Conciergerie) that have security checks that cannot by bypassed with the pass.
• Some people will try to sell you the Paris Visite card instead of the Paris Museum Pass.  Don't buy it - not a good value.

More Information

See the official Paris Museum Pass official website: http://en.parismuseumpass.com/