Twitter is one type of module.It's following feature.
1) easy to use interface
2)View recent activity and mentions
3)Post messages, replies, and re tweets
4) Multiple sizes and themes
Twitter has always helped me when in need. I also actually helped another site out by just tweeting about various things they were doing just cause I needed to tweet about something, and they actually congratulated me for it haha..
I was honored actually, cause for the simple fact, I was doing it for the heck of it.