There are two ways to build your own binary clock.
1.- One is to make your own PCB. Learning a bit of micro controllers. Have a micro recorder. Some experience in electronics and putting hands to work.
2.- But. If you like electronics and you do not have time for all of the above can use this instructable. Just go to ebay purchase a kit of construction and welded parts.
This KIY is designed for people with little or no experience on electronics. Who want to start in this world.
There is the ebay place: http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&ssPageName=STRK:MESELX:IT&item=250375293631