Official Gmail Blog: Create personal mailing lists through contact manager

Google Mailing Lists: New feature in GMail.

Google again..adds another useful feature to its one of the most widely used products, GMail. Remember those e-mails that were sent out to everybody in a particular department about an announcement, in your last organization? Of course, that is done using Mailing lists. E-mail addresses of all the relevant recipients are added to a mailing list and then, you never need to worry about who hasn't received an important message.

Gmail now supports customizable mailing lists, to which you can add e-mail addresses from the list of your GMail contacts. Once you add your contacts to mailing lists, you are ready to send a common message to all contacts in your mailing list. All you need to do is, entering the name of that group to the To field while composing an e-mail to be sent to the mailing list.
This saves you the hassle of picking each one of the intended recipients before sending mails. Also, this automatically eleminates the possibility of not adding some e-mail addresses while sending messages.

Mailing lists can be used for various personal and professional purposes. For example, you can send invitations for your evening parties to all invitees without missing anyone. Or, you can send quick and easy update about the change of your contact number to all the important people. Well, there is an endless list of applications of mailing lists to your daily lives. So, it's here for you to check out.

You can find the detailed instructions on, how to create a mailing list in GMail from Official Gmail Blog: Create personal mailing lists through contact manager