Mozy offers free back-up accounts with 2 GB free space. Like a classic, "but wait there's more" trick, it also offers 256 MB additional space for "referrals" to both the person who refers and the person who is joins.
Mozy says it applies the referral when the person who joins actually starts backing up. Here is a link if you want to give me (and yourself) 256 MB of additional space:
A cursory web search shows that EMC (NYSE:EMC) owns Decho Corp. which in turn owns Mozy. (The above has not been confirmed from any source. Please use common sense when investing!)
I do not own any interest in NYSE:EMC as of this writing.
Update: I must mention that Michael Horowitz has a two-part article on " Everybody likes Mozy--except me".