Given the seemingly endless popularity of the DIY movement, awareness of green practices and recycling as parts of the design/build process and the high cost of new materials, salvage businesses continue to thrive:

• Chicago-based Salvage One, established in 1979, sells ... well, everything. And anything. Arts & Crafts furniture & fittings, A&C stained glass, fountains, doors, bath fixtures and columns - and that only scratches the surface.
• Minneapolis' City Salvage has a large stock - especially of art glass - at their First Avenue warehouse; they also have a blog "for the edification and enjoyment of all."
• Recycling The Past in Barnegat NJ has a good stock of the usual ephemera, plus lots of Indian salvage, tilenew furniture made from recycled / reclaimed wood and iron.
• The Old House Parts Co. in Kennebunk ME specializes in hardware, but they also have a ridiculously large stock of woodwork, fixtures & millwork.
• In Susquehanna PA, we find Conklin's barnwood & hand-hewn beams, which sells just what you'd expect. Whether you're looking for flooring or decorative and structural beams, they have one of the largest stocks I've ever seen, in a dozen different types of wood.

and in the UK, where architectural salvage is a way of life:

• Cheshire Demolition "offers one of the biggest salvage and reclamation yards in the North West. They offer everything from reclaimed doors to fireplaces."
• The Salvage Doctor specializes in the "reclamation and restoration of cast iron architectural salvage and antiques," and carries an extensive range of radiators (cast iron, school- / hospital- /column- style, etc.), fireplaces & surrounds, woodburning stoves, rainwater systems (guttering, downpipes & fittings), gates and railings. They are located in Horsham, West Sussex.
• In Situ trade out of their Manchester ex-pub warehouse and studio. They keep a large stock of the usual - with attention to fancy pavers, lighting, glass, flooring, entryways and doors / door furniture.
• Cox's Architectural Salvage has operated their 12,500 sq ft covered warehouse in Moreton-in-Marsh since 1992. They are one of the largest Victorian ironmongers in Britain, and also refinish and sell their own line of nickel plate and brass hardware.
• Toby's Architectural Antiques has shops in Exeter and Newton Abbot. They carry a wide range of exterior detail - gates, ironmongery, roofing, slate, stone, water features - as well as kitchen materials, doors, light fixtures etc.
• Park Royal Salvage at the Lower Place Wharf in London sells everything from building materials, doors, windows and reclaimed plumbing to doors, windows, fireplaces and other old house parts.
• Robert Mills Architectural Antiques are one of the more specialized shops of their kind, with an especially large stock of architectural woodwork, mainly panels, columns, balustrades, mouldings and friezes, window frames, etc.