Box.net is giving away 1G of free online storage just for signing up.  Sign up now before they stop the offer -- 1G of online storage is very valuable and is extremely useful for keeping your critical data backed up at an offsite location.

If you look deeper at this offer you will see an excellent business model:  Gather a large user base with a free, hot product and then offer upgrades to even better products and services.  With a large enough user base you can sell the entire business to someone larger like Yahoo or Microsoft (just like Hotmail did back in the day).