title: Google Apps Marketplace SDK : Gadget for calendar
body: <p>We're willing to write a Google gadget installed through Google MarketPlace that would integrate into the Google calendar GUI.
  We want to add a button in the event form displayed when creating a calendar appointment.</p>
  
  <p>We have no clue where to start and if it's feasible.
  The Google marketplace sdk doc talks about COB (gadget for gmail) but nothing about calendar GUI interaction.</p>
  
  <p>Any idea where to start?</p>