Twitter

he help page on Twitter was quite informative for a first time user like myself! One of the cool things that I noticed was the search bar on the footer. As mentioned on the help page you can pretty much search anything and you will get updated-real time results. Also you can even find out who is tweeting in your city!
If you want to import your address book you have the option to do this as well using the Find people link. If anyone in your address book has an twitter account, then they will be notified that you want to add them and follow their tweet.
Another good feature is the fact that you can protect your profile from certain people. It is defaulted to be public, however you can customize your settings to your preference.
Everything is real time with twitter so if you want to search about a topic, it would give you up to date information- not old news.
My favorite shortcut commands:
@username + message
directs a twitter at another person, and causes your twitter to save in their "replies" tab.

D username + message
sends a person a private message that goes to their device, and saves in their web archive.