Do you mean the Madrid Card, with discounts and passes for tourist sites, museums, restaurants, transportation and tours? If so go to
www.madridcard.com. It also has links for other cities, Seville, Barcelona, Burgos, etc.
I've decided to pick one up when I get there because it costs 17 euros to mail to the US, about half the cost of the card itself! It does, however come with a book and map which should be very helpful so I plan to pick it up at Barajas when I fly in.
When will you be there? I'll be in Madrid Sept 19-22. Some tours (not DiscubreMadrid) require a minimum and I am travelling alone on that leg of my trip. Perhaps we could team up for a tour/Flamenco show.