Personal EMP field generator: Puts out weak electromagnetic pulses, not enough to destroy all electronics but quite enough to disrupt or ruin cameras and tape recorders that come within five feet. Goodbye obnoxious mobs of reporters/fans. Market: Politicians, celebrities, victims of tragedy hounded by the media.
No-Grow Grass: It doesn’t actually *not* grow, but it’s genetically engineered to grow to a specific height and stop. There’d be a very short strain for athletic fields and people anal about their lawns, and a longer strain that’s friendlier to outdoor play.
Shock-sensor equipped cellphones: Instead of digging your phone out of your pocket when it goes off at an inappropriate time (at the movie, at a funeral, in the classroom, in the confession booth) you can simply slap it. The sensor detects the shock, and goes silent.
The Ruin-a-Spammer’s-Life Foundation: A small non-profit organization staffed with IT works who would take donations and use them to legally (no book of Job reenactments) torment the people responsible for our spam. If you donate enough, the foundation allows you to participate personally in a campaign.