Any way to test modem speed?

Just wondered if there was a way to write code into a front page to see how fast the user/modem is connecting at.

I know that you can, by choice, test your bandwidth speed, but didn't know if there was any way to do that behind the scenes... (just like tracking screen resolution, domain, etc.)

THANKS!

Here's a nice script for looking at your users' download times:
http://smartcgis.com/loadtimer/

MCookie... thanks again! I'll try that one!

Here's a little ditty (http://www.brothercake.com/scripts/modemspeed.php) - not desperately accurate, but good fun :)

some javascript speed tests:

http://homepage.tinet.ie/~leslie/testpage.htm

http://www.toast.net/performance/

http://www.numion.com/YourSpeed/Checkup.php