Lil Pun, To set the spreadsheet where nobody needs to sign in just click on Share and select Publish As A Web Page. It will create an HTML file and then you can post that URL in your messages.
OK, I tried that and here is the link it gave me: http://spreadsheets.google.com/pub?key=tzSmHWMReDmJXhKChohm2IQ&output=html This is not updated. Try it out and let me know if it works. Thanks.
Yup. Works for me. It's just like what fadeaway has for the Touchdown Survivor game. To edit it just click on Edit This Page at the very bottom and the original spreadsheet will come up. Make the necessary changes and then choose Save and Close and it will disappear. The HTML file will automatically update with the new changes within 5 minutes.