I write about this stuff on my blog. For eg. using Last-Modified for the same effect as the ETag in OP: http://www.nikcub.com/posts/persistant-and-unblockable-

I write about this stuff on my blog. For eg. using Last-Modified for the same effect as the ETag in OP: http://www.nikcub.com/posts/persistant-and-unblockable-cookies-using-http-headers http://www.nikcub.com/posts/persistant-and-unblockable-cooki... also posts with tips and more info in the archives: http://www.nikcub.com/archive http://www.nikcub.com/archive What I do is I use 3 different browser, 2 is ok. All your 'apps' such as webmail, facebook, etc. you use on one browser. Install Disconnect, AdBlock, NoScript etc. and disable flash, java etc. on the second browser and use that for all your web browsing. Kill the history and cookies on this browser regularly. Don't ever be tempted to 'browse' using the browser you have your apps logged in on. I have a third browser with flash enabled where I copy paste URLs into if I ever need flash for something, which is less and less often.