How to open google spreadsheet tab in new window or tab?

How to open google spreadsheet tab in new window or tab?

You can open the document twice and have the first tab set on the first sheet and the second tab set on the second sheet. All you have to do is go back to the Google Docs file browser and click to open the file again.
I have tested that:
=Sheet1!A1), if you edit
the first sheet in the first tab, the
second sheet will pick up your
change.A middle-click will open the spreadsheet from the google-doc file browser. (You can select what happens from a normal click via settings, either current window or new).
This does not however work once the spreadsheet is open, this has to do with the interface Google uses for the actual spreadsheet. Right now best as I can tell there is no way to do this.
A very clunky workaround is to open two copies of the spreadsheet via middle click (or left click if you have it set as such) and have each tab on a separate worksheet.
Perhaps if you already have the spreadsheet open you can drag its URL into the tab area (to open a duplicate) and then quickly navigate to other worksheet.
Well, by default you can't open it. Its JavaScript link, not a HTML link.
You may have to use extension like Greasemonkey (which can manipulate any page once they are rendered on your browser). For each specific manipulation you have to install a Greasemonkey script. (You can find lot of scripts here userscripts.org).
You can get Greasemonkey for forefox here, http://greasemonkey.mozdev.org/. I know that greasemokey has been ported to IE and Chrome, but never tried it.
Before you install Greasemonkey scripts, you check them for reliability, as there is very good chance that they steal information or passwords from your browser.
For your particular case you should be looking for some gs-script, which will replace the javascript links with wiki.greasespot.net/GM_openInTab function. However, looks like, in case of Google docs, problem might bit more complicated, even if you manage to replace javascript links with GM_openInTab, google docs may not behave as expected.
By far the easiest way (Confirmed in Firefox & IE) is simply to click on the document with the middle mouse button.
This works for all Google Doc Applications.