Customize the User Agent of most popular browsers

1.Chrome: create a shortcut with an user-agent argument: chrome.exe --user-agent="User Agent String"
2.Firefox: install the add-on user-agent-switcher

3.IE (8+): install the add-on UAPick

4.Opear: type opear:config into the address bar, go to "User Agent" and Click the question mark for help on setting "Spoof UserAgent ID"