My Android phone opens my garage door when I approach my house on my
motorcycle.

Background blog posts:

  - http://brad.livejournal.com/2394220.html
  - http://brad.livejournal.com/2394707.html

Some laters videos with newer hardware:

  - https://plus.google.com/u/0/115863474911002159675/posts/84h5DbJPTGs
  - https://plus.google.com/u/0/115863474911002159675/posts/j5FeJpASEXx

To use this, you need both the app on your phone, as well as the
hardware connected to your garage door. See server/README-hardware.txt
for details.