From Louvre's website:
<font face="Verdana, Arial, Helvetica, sans-serif" size="2">Title V / Taking of photographs, copies and surveys
Article 25
During public opening hours in the rooms of permanent exhibitions, you may photograph or shoot displays for private use.
Concerning temporary exhibitions, taking of photograph are prohibited, unless you hear to the contrary, mentioned at the entrance of the rooms.
Article 26
The use of flash-lights is not recommended. The use of lamps or any kind of lightning is forbidden.
The use of the cameras is forbidden in the room of the Monna Lisa and the Vénus de Milo. </font>
From d'Orsay's website:
<font face="Verdana, Arial, Helvetica, sans-serif" size="2">Photographic and film shooting
Any shooting using a flash, an incandescent lamp, a tripod or stand is forbidden except with special permission. </font>
[This message has been edited by yk (edited Mar 12, 2004).]