1) Stolen Item Recover Startup
(Came up with this when a friend's house was broken into)
User enters all serial numbers into one site. When items are stolen, they activate an alerts system that scours craigslist, ebay, etc... for the stolen items. They alert the owner when the item has been found.
2) Synonym Email Generator to Prevent Corporate Leaks
(Came up with this when I saw many corporate leaks)
When a sensitive corporate memo is sent out, this synonym generator inserts synonyms into the email, with a unique set of synonyms for each email. When a leaked memo is identified, the memo can be traced back to a particular user.