Does your Target= trick also work in reverse? For instance, I am trying to have the results of a search open in the main window. AKA I never want the sidebar to change, only use it as a launcher of sorts…

In any case, check out: http://developer.mozilla.org/en/docs/Code_snippets:Sidebar

Per their site you should be able to open/close/toggle it via:

/**
* Opens or closes the sidebar identified by commandID.
*
* @param commandID a string identifying the sidebar to toggle; see the
* note below. (Optional if a sidebar is already open.)
* @param forceOpen boolean indicating whether the sidebar should be
* opened regardless of it’s current state (optional).
* @note
* We expect to find a xul:broadcaster element with the specified ID.
* The following attributes on that element may be used and/or modified:
* – id (required) the string to match commandID. The convention
* is to use this naming scheme: ‘viewSidebar’.
* – sidebarurl (required) specifies the URL to load in this sidebar.
* – sidebartitle or label (in that order) specify the title to
* display on the sidebar.
* – checked indicates whether the sidebar is currently displayed.
* Note that toggleSidebar updates this attribute when
* it changes the sidebar’s visibility.
* – group this attribute must be set to “sidebar”.
*/
function toggleSidebar(commandID, forceOpen) {

In the upper-right corner of the Firefox sidebar is an X to close it. Is there a JavaSript that will close it in a link?

for example

javascript:closesidebar()

#browser { -moz-box-direction: reverse;}

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