Do you have multiple outputs on your PC?  I have a USB headset and a speaker output.  I like to keep my USB headset plugged in.  Switching between the two quickly is a right pain in the backside.

Here are some ways you can quickly switch between headset and speakers.

I use Soundswitch x64 (there is also a 32 bit version).
http://blog.contriving.net/2009/05/04/a-hotkey-to-switch-between-headphones-and-speakers-soundswitch/

There is also another application called “Sound Switch” – same name, different program.
http://soundswitch.codeplex.com/documentation

And, there is “Quick Sound Switch”.
http://www.quicksoundswitch.toflo.de/eng/index.html

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.