Have you ever worked on a big solution? sometimes with many projects?
Going back and forth in the solution explorer could waste a lot of your time, if you're a bit tired just before getting a version out its even worse, not to mention getting you out of focus.
I'm a big fan of Quick Open File, I think you will too when you try it.
Just remember Ctrl-K O and type the file you're looking for.
Update 2012-08-22: You can always use the Navigate To, or Ctrl+, key combination:
I've discovered this while looking for a similar solution in VS2012, its showing too much information, but its better than digging through the solution files and you can always type the extension.