I will be travelling to Madrid with my girlfriend soon. Does anyone have information about the attitudes toward gay couples with regard to accommodations? Will we be looked at strangely for reserving a single bed, etc.?
Any advice would be greatly appreciated!

This is an incredible resource, MadridMan!

There's already an extensive thread on this (do a search on the board). There, you will be reminded that in Spain 99% of hotel and hostels have the two-twin bed arrangement (often pushed together for the 'effect' of one bed). Two women traveling will have no trouble whatsoever. You should check out the timeout.com on spain and clue yourselves in on lesbian friendly places in spain, of which there are lots.

Hi, ellen--
I agree...your chances of finding a double bed are slim to begin with! Nobody will look askance at you for checking in with another woman, I imagine. Women travel together all the time, in all sorts of relationships ranging from moms and daughters, to sisters, to friends, to couples.
Have a great trip!