The ShuttlePro MultiMedia Controller is by Contour Design and puts your favourite keystrokes at your fingertips. I love it!
“...As a jog & shuttle controller, the ShuttlePRO offers timeline accuracy that a computer mouse and arrow keys can't deliver, and its programmable buttons let users work faster and easier than ever before by placing total control at their fingertips ... You can also configure or customize the ShuttlePRO for any application; program keyboard shortcuts, scrolling, modifier keys, and virtual keys with no hassles...”
Griffin Technology's iMic is a stereo sound input/output USB device you can plug headphones or microphones into.
“...
the iMic supports both line and Mic level input as well as line level output
for any USB capable computer ... By using USB, the iMic provides significantly
superior audio input and output performance over built in audio...”
Final Cut Pro links 
Is also bundled with the Shuttle Pro
