With a bulletin board, you can post and respond to messages on a website, without having to clog up your e-mail box. A newsletter gives you the opportunity to stay in contact with many people in your network all at once and on your own time. It is not as personal as a handwritten note or an e-mail, but it keeps your contacts abreast of what you are doing, and let's them know what's new. Newsletters do not have to be fancy. You could create a newsletter with special publishing software, such as Microsoft Publisher, or create a simpler format using any standard word processor.
Substance is more important than style.
Use your newsletter to mention articles you've published, presentations you are scheduled to give, workshops you plan to offer, or even personal milestones such as birthdays, anniversaries, promotions, and recognitions. Granted, setting up the newsletter the first time may be time consuming, but once you have your mailing list created and the newsletter template in place, it is easy to maintain and update. Here are some more networking books for additional suggestions. Reviews of these and other networking titles are welcome. The only networking book you'll ever need.