I'm just messing around my shell just because in my new macbook laptop, the meta key doesn't work on the terminal. So there is no way to move around words with bash (Meta+f / Meta+b).

Finally found a way to work around this (it was driving me mad) just open the preferences on iterm -> Profiles -> Keys (tab) -> Left option as +Esc

http://stackoverflow.com/questions/196357/making-iterm-to-translate-meta-key-in-the-same-way-as-in-other-oses#comment1042379_438892