IE6 - Go to Tools-Internet Options. Next you should see a 'Temporary Internet Files' block. The two buttons here you should be concerned with are 'Delete Cookies' and 'Delete Files'. Click on 'Delete Cookies' button and click 'yes'. Then click on the 'Delete Files' button and select 'delete off-line content' and then click 'ok'.
You should also see a 'History' section you should set this to 1 day and then click on the 'Clear History' button.
IE7 - From the tools menu select the 'Delete Browsing History' and click 'Delete All'.
FireFox 2.x - Got to Tools-Options-Privacy. You should see a 'Private Data' section, make sure the 1st box is checked and click settings button in that view. A box with a few selections will show up. I would recommend you check all the boxes.
Remember that when you delete cookies that you could remove some settings that you are used too when you go to websites. For example you may have auto-login on this site if you remove the cookie you will need to login manually when you visit the site next time. This is the same about deleting the password info. Now only keep this info if you trust everyone around you or the computer is used by just you.
If you have prying eyes or in a unsecure area where people could have access to your machine you should always logout of the PC or lock the computer before leaving. Or at the least have a screensaver with password security.
Have fun
-D1-
