Suppose you would like to set Orkut, Google and hackingtips.in as your homepages. Then try this tweak in Firefox to set multiple homepages. It can be done as:
  • Goto Tools>Options>Main
  • In the When Firefox starts drop down menu choose Show my home page
  • In Home page give your homepages separated by a | (pipe symbol)
Example: http://www.google.com|http://www.orkut.com|http://techian.com
  • Click OK
Now next time when you start Firefox all of your three home pages will be displayed simultaneously.