aristotle - 9:33 pm on Jan 30, 2011 (gmt 0)

had some vague feeling about synonyms in content, but never though about it for titles; good idea

In my opinion substituting a synonym for an important keyword in the page title is more likely to hurt than help in most cases. I prefer to put synonyms in the main header and the content. I believe that the title should contain the keywords that you're targeting.