The following uses for hafnium are gathered from a number of sources as well as from anecdotal comments. I would be delighted to receive corrections as well as additional referenced uses.
Hafnium is used for alloying with iron, titanium, niobium and other metals. The metal is used for nuclear control rods and is an efficient "getter" for scavenging oxygen and nitrogen. It is used in gas-filled and incandescent lamps.