Hoople - 2:19 pm on Apr 23, 2012 (gmt 0)
What you propose is sound for most. I have seen here and advocate myself the concept of 'joining the niche neighborhood'. How? Well, what you've already stated plus:
Ask for a link on your niche's 'authority site'.
Add your site to your niche's directory.
Add your site to the well trafficked local portals.
In some niches the Forums where your widget is discussed still has value. Join in on answering the questions with a modest signature link block. Avoid the fan boy type of replies - don't even mention you have a site unless a page on it has an authoritative answer to the thread topic's question.