As to the client side in the browser, any code that does this will have some IE-specific stuff; that's just how XMLHttpRequest is implemented. But that's generally abstracted away by the thinnest layer on top of it; see this for code that works in all browsers.
Ping & DNS - updated with new look and Ping home screen widget
Joined: Dec 18, 2008
I have it working perfectly. I will post more details when I get the time. Check back in a couple of days if you're interested. [ January 02, 2009: Message edited by: David Westbrook ]