A pocket door is a sliding door that disappears, when fully open, into a compartment in the adjacent wall. Pocket doors are used for architectural effect, or when there is no room for the swing of a hinged door. They usually travel on rollers suspended from an overhead track, although some also feature tracks or guides along the floor. Both single- and double-door versions are used, depending on how wide an entry is desired.
Furthermore, installing a pocket door rather than a hinged door can add an average of ten square feet of floor space, according to building expert Tim Carter, who considers the pocket door "one of the top ten most overlooked items when many architects and builders plan a home". The doors were particularly common in Victorian homes to close off such areas as sitting rooms or dens; however, as architectural tastes changed, many of the hardware manufacturers went out of business. With improvement in the hardware and the growth of the market for condominiums and town homes, there has been a resurgence of interest in this space-saving feature. Modern residential uses include bathrooms, closets, laundry or utility rooms, or home offices. A wall-hung variation called an "open pocket door" may be used where in-wall installation is impractical; this version is recommended for homes with disabled residents due to greater ease of opening compared to traditional hinged, pull-open doors. One downside to pocket doors is hidden parts and hardware, which can make them difficult to replace or repair when something goes wrong. Fixing the problem might require removing the door and trim and opening up the wall. 
The 1953-'54 Darrin sports car used pocket doors.
- "Installing Pocket Doors," Ask the Builder http://www.askthebuilder.com/489_Adding_Pocket_Doors_in_an_Existing_Home.shtml
- Interior Doors Direct http://www.interiordoors.com/pocket.html
- "When organizing a closet, consider a pocket door," Vallejo Times-Herald http://www.timesheraldonline.com/homeimprovement/ci_3651804
- "Wall-hanging version of sliding door available," Vallejo Times-Herald http://www.timesheraldonline.com/homeimprovement/ci_3651801
- "How to Repair and Replace a Pocket Door," Ron Hazelton's HouseCalls http://www.ronhazelton.com/article/home/windows/UDIzMQ/How_to_Repair_and_Replace_a_Pocket_Door_
"Pocket Door Installation," DIY to the Rescue http://www.diynetwork.com/diy/hi_bedrooms/article/0,2037,DIY_13904_2684878,00.html
"Animated installation of a pocket door," http://www.portman-pocketdoors.co.uk/pocket-door-system/portman-video/