It's often the case that you want and need to be creating a database to store your data, but Google Spreadsheets are just so handy aren't they? But Google Spreadsheets are very good at relational data. Here's an example where, you want to have one column for the name of your recipe and another for the ingredients ( comma separated ). How you use this script is you click on the cell you want to be relational and choose the Admin > Show Relationship Editor. This opens up a dialog window showing you all the options included so far. You then alter the ingredients and it saves a comma separated list into the spreadsheet. Here's the spreadsheet . Use File > Make a copy to see it work and rummage around in the code. If anyone can help make the UI prettier I'd be grateful, thanks.
Collaborative Tools Project