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When gadget is created, submit to a directory: advertising from Google directory and main library website
You can embed iGoogle gadgets in other things without requiring people to have an iGoogle account (as long as it handles javascript, you can put it in LMS, LibGuide, websites, Google Wave, etc)
You can sign up for a developer account to get a sandbox to play in
Google Gadget Editor: code.google.com/apis/gadgets/docs/tools.html#GGE
Google Gadget Sandbox: google.com/ig/sandbox/
Don't have to be a coder; can just plug and play as long as you know flash file or feed name; others require HTML/XML, CSS and Javascript skills; they make code available
Markup and tags: <ModulePrefs>-Gadget settings; <UserPref>-User personalization (customized databses);