A signature file is often the most overlooked form of promotion. It is a method of discretely advertising yourself and your website which is accepted across the Internet. A signature file should be at most seven lines long and roughly 60 characters wide.

Your e-mail sig. file should always be a compelling headline.

Considering that email marketing is such a highly effective medium and it's used on a daily basis a powerful headline is a necessity. Extremely long signature files that scream out to a reader "I'm an ad and I'm trying to sell you something" are less likely to produce the response that a short attention-grabbing headline will.
 

Sample SGR Email signatures (add your own to the comments to help other SGR Affiliates):

Just when you thought you knew the Secret...
http://thesecretuniversity.com

p.s : I've been dying to share this with you...
http://thesecretuniversity.com

Learn the Law of Attraction
from the teachers featured in The Secret!
Bob Proctor, Rev. Michael Beckwith and Jack Canfield
How to Master the Law of Attraction and Make it Work for You.
http://thesecretuniversity.com

I use a combination of 1 and 3 at the moment but will get more
inventive when I have time :)

(P.S. replace with your URL of course, not mine)

Where to post?

1) Do a Google Search for "allintitle:the secret filetype:html forum" to find forums about "The Secret" (replace "the secret" with law of attraction, sgr, science of getting rich, etc).

You only want to post to related forums or you'll just be wasting your time.

My updated secret-vault of bookmarks for finding people with problems:

• Embarrassing Problems Finding embarrassing health problems
• Health_Problems Common health problems & natural solutions
• Do It Yourself Auto, Interior, Exterior, Decorate, Electric, Flooring, Hardware, Garden, Household, Lifestyle, Plumbing, Real Estate
• eHow.com articles on how to do just about everything
• A Hints and tips Website People send in their tips
• PageWise.com answers to questions real people ask
• Tipking Household tips hints and frugal ideas
• Yahoo! Answers Ask a question on any topic and get answers from real people.
• Google Answers Researches answer questions for payment.
• FinditQuick Answers People pay to get their answers.
• Internet FAQ Archives Internet FAQs archive
• Weeno Articles to help people learn things they didn't know.
• Knowledge Hound Finds and lists How-To's
• ThriftyFun.com Forum with open discussions on problems or ideas -- and solutions from forum readers.
• Complaints.com Finding out what people complain about in regards to businesses.
• AllExperts Largest free Q&A service on the net.