Steven,

I'm not sure if it will work on a non sharepoint web page but what I did,
was create a hidden webpart in sharepoint for the form library, make sure to
use full menu.  Then get the Javascript call when you mouse over the "Fill
out this form"   in the webpart.  You can only do this in the edit mode for
the web part page because the web part will be invisible in normal mode.  The
javascript will have a unique call number.  You can then create a button that
invokes that javascript call.  Again, I don't really think it will work on a
non-sharepoint page because I think you need those javascript files or at
least linked to them.  But it at least gives you a starting point.

--Patrick