Google has updated Google Spreadsheets with new features such as:

-support for Open Document Format (handy for those who use linux-based machines and Open Office products)
-a way to force multiple line text in a single cell (like a street address in, say, a spreadsheet for planning a wedding)
-currency symbols in addition to $
-an option to create PDF files that will print nicely
-the ability to share a spreadsheet with anyone who receives the URL (without having to specify their email address).