Want easy Google Spreadsheet script to geocode addresses and export as GeoJSON? Thanks to @developmentseed here it is

...We’ve developed an add-on script for Google Docs Spreadsheets that lets you geocode arbitrary addresses and export spreadsheets as GeoJSON, a file format that works in TileMill.

This Development Seed script is hosted on GitHub, and seems pretty accurate. It works with Yahoo! (API key required) and Mapquest geocoders.