More playing with online spreadsheets.
Here's a cute example. This is an EditGrid spreadsheet that pulls book data from Amazon (including price in dollars), currency data from Yahoo, and then calculates the price in pounds of the books. It's a "calculator" meaning that I've set up only one field to be editable (the search term for the book, in the white cell) and you can change this in your local copy, without it changing my original.
Looks like spreadsheets really are evolving to be the online user-programmable dashboards which people can use to create and publish their own mashups and other software. Very exciting.