To easily switch between application, I've installed skippy-xd, which works a lot like expose on OSX, showing previews of all the applications that are currently running.
Skippy-xd can be found here and can be installed using make && sudo make install.
You can change the settings in /etc/xdg/skippy-xd.rc. My skippy-xd.rc file can be found here.
I used xbindkeys to make a shortcut to a simple shell script that will open skippy-xd, or kill the process if it is already running (instead of opening another instance).
#!/bin/sh
if ps ax | grep -v grep | grep "skippy-xd" > /dev/null
then
pkill skippy-xd
else
/usr/bin/skippy-xd
fi