The best way to log into your Facebook from mobile is by using application made for your mobile. Easiest way to find application for your mobile is to visit with your mobile browser website http://m.facebook.com/ where you will see a link, after you login with your Facebook username and password, on the bottom of the page saying “Download Facebook for your (mobile name)“. Facebook automatically recognizes your mobile name and clicking the link transfers you to the download page for the Facebook mobile application suitable for your phone.
Generally mobile apps are divided by the operating system of your phone so we have application for iPhone, Android, Windows Mobile, Symbian and other. Application can also be found in the app marketplace for your phone brand. But newer phones already have Facebook app preinstalled when you buy your phone.