It's used in catalytic converters.
Lithium is used to make lithium-ion batteries, and lithium carbonate is used as a medication for bipolar disorder.
Everything: nuclear power fuel (cells) water hydrogenation (ex: saturation of fats) All organic compounds
Used for bombs, signals, and flares
It is often used to prevent corrosion of other metals and is used in many alloys. Source: http://en.wikipedia.org/wiki/Tin