Google spreadsheet can be used as a pseudo-database when setting up a more formal mySQL table is more than you’re looking for. I was looking to write a simple app that pulled in email addresses and sent a short email (it will be run on a monthly cron as a reminder). I wanted to easily be able to manage those email addresses. Google Spreadsheet was the ticket.
See my code below where I access the sheet, pull out the second row, and sends an email to any string the qualifies as an email address.
Consult the Google Spreadsheet API for more access methods. I am using the “cells” feed.
In order to access the sheet with PHP I had to set the sheet to “public”. There is probably a way to create a secure connection with an Auth Token, but that was the not the purpose of this exercise. The key for your spread sheet can be found in the URL of the sheet when you have it open in the browser.