The following uses for niobium are gathered from a number of sources as well as from anecdotal comments. I'd be delighted to receive corrections as well as additional referenced uses (please use the feedback mechanism to add uses).
Niobium metal has a number of important uses. It is a component of some stainless steels and also alloys with nonferrous metals. These alloys have good strength and other properties, and are used in pipeline construction. The metal has a low capture crosssection for thermal neutrons and so finds use in the nuclear industries. The metal is used in arc-welding rods for some grades of stainless steel. It is used in advanced engineering systems such as those used in the Gemini space program. Some magnets contain niobium and superconductive magnets are made with Nb-Zr alloy wire. Because of its bluish colour, niobium is apparently being used for "body art" products, such as navel rings.