Buy This: Logitech QuickCall USB Conference Phone for $10
Caveat: None of the controls actually work in windows 7 (it just shows up as a record and playback source in your regular control panels), and you need to install JUST the driver, not all the logitech crap. Great instructions and a link to the drivers are here:
The sound quality of both the Mic and Speakers is LOADS better than just using the mic and speakers from a laptop. I got tired of wearing a headset all day, so I bought one, and I cannot recommend it highly enough.