These URLs work even on a normal browser.

http://google.com/m/
https://google.com/voice/m
http://m.google.com/?dc=mgcgo&hl=en

http://m.google.com/gwt/x?u=<url>
    eg:  http://m.google.com/gwt/x?u=http%3A%2F%2Fsearch.twitter.com%2Fsearch%3Fq%3DChicago