or <META HTTP-EQUIV="imagetoolbar" CONTENT="no">

To let the user manage it themselves, it's called "Enable Image Toolbar" under Tools->Internet Options->Advanced->Multimedia, which makes for a great Google search term ;)

Also of possible interest:

[link|http://msdn.microsoft.com/library/default.asp?url=/workshop/author/dhtml/reference/properties/galleryimg.asp|http://msdn.microsof...es/galleryimg.asp]

[link|http://msdn.microsoft.com/library/default.asp?url=/workshop/misc/mypictures/mypictures_ovw.asp|http://msdn.microsof...ypictures_ovw.asp]