I went ahead and attended one as guest. It was definitely worthwhile and and I became a member and have delivered my first speech.
It is obviously about public speaking, however it is useful in many ways:
-The core approach is to do a series of 10 speeches with each focusing on a certain aspect of speaking (Speech organization, Body language including eye contact, Vocal variety)
-You will automatically find your own areas which need focus, be it planning for a speech, english language, fear of being in front of an audience.
-There are stories to hear and things to learn from other’s speeches. I enjoyed one about the Mexico desert where the stars touch the ground at the horizon and look forward to others. I look forward to it.
-You become part of a highly motivated and ambitious group.
-There is a leadership track with 10 activities, if you choose to go on that instead of or in addition to the public speaking one.

I would recommend it and am glad I added it to my todo list when Steve Pavlina mentioned it in his blog.

If you would like to find a club near you, please use the following link: http://www.toastmasters.org/find/default.asp