Lithium is pretty much just a boring element. It sits there, between hydrogen and sodium, but with none of the coolness of either of those. It's not really a very common element; you would find it mostly in lithium-ion batteries that are used for laptops and other portable electronic devices. Soon to be surpassed by fuel cells. So where does this leave lithium? About the only interesting property it has is its high specific-heat capacity. It's used in some alloys with aluminum, sometimes. In the movie Apollo 13, the air filtration canisters used lithium hydroxide.
That's about it for lithium. If anyone knows of other uses of it... anything that would make it more interesting... feel free to mention it.
P.S. Dilithium and trilithium have nothing to do with lithium, because both of them don't actually exist.