what is the usage of Robots.txt file?

The Robots.txt file is used to restrict the search engine crawlers from indexing the selected (Private, confidential and admin pages)areas of your website.

Keyboard Short Cuts for New Twitter

The shortcut keys of new Twitter is following

Actions

Favorite : f
Reply : r
Retweet : t
Direct Message : m
New Tweet : n
Toggle Details Pane : enter

Navigation

Next Tweet : j
Previous Tweet : k
Page down : space
Search : /
Refresh Tweets And Back To Top : .

Timelines

Home : g h
Replies/Mentions : g r
Profile : g p
Favorites : g f
Messages : g m
Go To User : g u