Occasionally, you might find that you have to send files that are bigger than what your email capabilities allow. Artists, graphic designers, software designers, professional photographers, writers, and architects are just a few of the many types of businesses that need big file sending capability.
YouSendIt.com allows users to send files up to 1 Gigabyte for free. (They earn their revenue through advertising, which the receiver views). There are also paid business memberships providing ad-free 2 Gigabyte file transfer.
It's a great way to send those huge documents you might not be able to send otherwise.