Position-traded money market funds are a different type of lock-up: Investors must place a trade to get into or out of the fund, which can take a day to complete.

FORBES: Not All Cash Is Created Equal

Not the type of songwriter to lock himself in a room until he's finished, Birdlips' Cliff Usher gathers the pieces for his songs from wherever he travels.

NPR: Birdlips: A Profound Little Travelogue In Song

The key was not to try to dig a Suez-type of canal, a great sea-level trench from ocean to ocean, but to create a lock-and-lake canal, where the ships are lifted up by a series of locks to a man-made lake, and then they sail across that lake, and then they are set back down on the other side by another series of locks.

FORBES: Fact and Comment