Some startups are nothing more than fads. They get a lot of buzz when they launch -- either by raising huge rounds, having famous founders, or being posed as the next Facebook killer -- then they go MIA.

Some fail, some quietly grow, and others pivot into new ideas.

We racked our brains for 10 startups that generated national buzz then fell of the face of the earth.

We also learned what they've been up to since their 15 minutes of fame ended.