Switch sound output using hotkey
Here are some ways you can quickly switch between headset and speakers.
I use Soundswitch x64 (there is also a 32 bit version).
There is also another application called “Sound Switch” – same name, different program.
And, there is “Quick Sound Switch”.
I can only speak for “Soundswitch x64″ in the first link, since this is the only one I’ve used. It is painless to use, (switch between output devices using ALT+CTRL+ENTER) and it is very stable. I have not experienced one crash with this application and have used it for over a year.