From Regional Knowledge Resource Kit
Twitter is for staying in touch and keeping up with friends no matter where you are or what you’re doing. For some friends you might want instant mobile updates—for others, you can just check the web. Invite your friends to Twitter and decide how connected you want you to be.
The Twitter blog allows you to keep up with changes in Twitter as a product.
For more information on how Twitter works click here
For information on how to get started and make the best of twitter click here

