Many websites use User-agent to determine the browser type, if it is a 3G mobile phone, display the contents of the mobile page, if it is a normal browser, display ordinary Web content.
Google Chrome, which can be conveniently used as a 3G phone simulator. In Windows "Start" and "Run" enter the following command, launch Google Browser, you can simulate the corresponding phone browser to access 3G mobile Phone Web page:
Google android:
Chrome.exe- -user-agent= "mozilla/5.0 (Linux; U Android 2.2; En-us; Nexus one build/frf91) applewebkit/533.1 (khtml, like Gecko) version/4.0 Mobile safari/533.1 " 
Apple iphone :
Chrome.exe--user-agent= "mozilla/5.0 (IPad; U CPU os 3_2_2 like Mac os X; En-US) applewebkit/531.21.10 (khtml, like Gecko) version/4.0.4 mobile/7b500 safari/531.21.10 " 
Nokia n97:
Chrome.exe--user-agent= "mozilla/5.0 (symbianos/9.4; series60/5.0 nokian97-1/20.0.019; profile/midp-2.1 configuration/cldc-1.1) applewebkit/525 (khtml, like Gecko) browserng/7.1.18124 " 
Try it with Android, IPhone, Nokia access http://www.163.com/, http://blog.s135.com/, http://www.google.com.hk/, HTTP/ 3g.qq.com, http://t.sina.cn these 3G mobile Web pages to see what's different.
Use Google Chrome as your phone simulator