http://gotfreestuffs.blogspot.com/2010/03/free-data-or-connectivity-speed-test.html
I used to test using this web, but it might not work on Phone that don't have flash (especially iPhone!). The link above don't use flash, so it is good for PC/laptop/phone and iPhone that don't support Flash!
http://www.speedtest.net/
p/s: See also making fun of iPad from worldwide
