To respond to Doug's question at the meeting yesterday.
While I typically haven't used a wizard to make the .nsi installer scripts I almost always use Notepad++
(
http://notepad-plus.sourceforge.net/uk/news.php?lang=uk)
which supports syntax highlighting for it and one click compilation(Not sure if Textpad has support for NSIS). I have however had luck with the HM NIS Edit tool in the past which is a more wizard based frontend.
See this page for more details.
http://nsis.sourceforge.net/Category:Development_Environments
Alex