This script did it for me: (thanks to whoever created it!)
var navOpenInBackgroundTab = 0x1000;
var oIE = new ActiveXObject("InternetExplorer.Application");
oIE.Navigate2("http://blogs.msdn.com");
oIE.Navigate2("http://blogs.msdn.com/tonyschr", navOpenInBackgroundTab);
oIE.Navigate2("http://blogs.msdn.com/oldnewthing", navOpenInBackgroundTab);
oIE.Navigate2("http://blogs.msdn.com/ericlippert", navOpenInBackgroundTab);
oIE.Visible = true;
Replace the http links in the above code with yours (create more lines as needed) and save it as whatyouwant.js. Double click it. There you go.
You can place your new .js file in the startup folder to run at startup.