I post this both as a tip and as a lesson that even IT guys can sometimes miss the obvious:
I’ve used Firefox for years, and one of my favorite things about it is the “session saver” feature. If you have ten eBay tabs open, you can close Firefox and those same ten eBay tabs will reload the next time you open Firefox.
But I never figured out how to restore multiple windows. If you have, for instance, one window with ten eBay tabs and another window with five Amazon tabs, you have to choose which window you want to close first, as only the last window will be restored. So if you close the eBay window and then the Amazon window, only the Amazon tabs will be restored. Or if you closed the Amazon window first, only the eBay tabs would be restored.
And then it hit me last night: if you close Firefox by clicking File > Exit (or, in Firefox 4, Firefox > Exit), the browser will restore multiple windows when you restart.