Kurosawa's influence and the things he was influenced by extends to a lot of surprising areas.
The Hidden Fortress is cited by George Lucas as an important influence on Star Wars - it's told from the point of view of a mismatched pair of wandering samurai, the R2D2 and C3PO of the film, and the plot involves the rescue of a princess and attacking the "hidden fortress" (i.e. Death Star) of the title. In fact, the name "Jedi" supposedly comes from the Japanese word "jidai" (era). The phrase "jidai geki" is used to describe period films such as Kurosawa's works.
Yojimbo was remade by Sergio Leone as A Fistful of Dollars - although Yojimbo itself was supposedly influenced by the 1929 Dashiel Hammet novel Red Harvest. The character played by Mifune is the inspiration for Clint Eastwood's Man with No Name.
The Seven Samurai was remade by John Sturges as The Magnificent Seven.
As previously mentioned, Throne of Blood is Kurosawa's version of Macbeth and Ran is his version of King Lear. Ran is noticeable for its realistic portrayal of Sengoku period samurai (as opposed to the more stereotypical samurai often found in other literature).
I'm sure there's lots more but these are the only things I know off the top of my head.
For Yojimbo and Mifune fans, Mifune plays a similar character in the Zatoichi crossover Zatoichi meets Yojimbo, which is available subbed on DVD.
