How do I search the open buffers in Vim?

Or

:bufdo vimgrepadd threading % | copen

The quickfix window may not look good for you but it's a hell of a lot more functional than ST2's "results panel" if only because you can keep it open and visible while jumping to locations and interact with it if it's not there.

ack and Ack.vim handle this problem beautifully. You can also use :help :vimgrep. For example:

:bufdo AckAdd -n threading

will create a nice quickfix window that lets you hop to the cursor position.