Someone from the Microsoft Excel team should read this page.

Quoted: t is so inefficient to always send the most updated spreadsheet to-and-fro using email, and I tried the "Publish" feature that Excel provides, but others can only view and not edit and save the published spreadsheet. [Google Docs & Spreadsheets] has all the features I am looking for so I can now communicate, work, edit our spectacular trip to Alaska and have everyone's research for the trip saved, without worrying about having the spreadsheet overlapped by another user who is also working on the file at the same time.