Bible Gateway now includes the Douay-Rheims bible with the Deuterocanonicals (they even call them that). You have to go to the bottom of the page and click on "include" because they don't want Protestants accidentally searching Catholic bibles :-) but it's great that they have the books now. It's a little strange (but not entirely) that they don't have the King James Version of the books. It's not well known in Protestant circles that when the Authorized Version (KJV) was published in England, by law it was required to include the Deuterocanonical books. They are part of the KJV, even though most Protestant bibles don't include them anymore.
This is a good alternative to the pathetic search interface the USCCB NAB has. Man, I hate that site.
I cannot remember ever finding the BibleGateway useful, but was pleased a while back to discover the Unbound Bible, which also includes the Douay-Rheims, as well as both the Clementine and Neo Vulgates (among bunches of others).
De gustibus non est disputandum I suppose.