Background: Many apartment buildings have callboxes. Modern callboxes have replaced the old speaker on the wall to cell phones where you can "buzz" someone up by hitting a digit on your phone. This is the perfect use case for Tropo's IVR. Pointing the callbox to Tropo allows the script to authenticate the user and let them in. The script also sends a text to the apartment owners cell phone letting them know their guest has arrived. This could easily be expanded to include the guests name.

Instructions: Once you have a Tropo account, you'll need to setup a new application and phone number and have your apartment's maintenance replace your cell phone with your Tropo number. Just add in the script and presto!