Zenith 5000 btu window-mounted air conditioner
Price: $115 obo

This air conditioner has been a life-saver for me while I've been at Stanford. Has adjustable sides, so fits a range of window sizes. If you come from a colder place, like I do, then having AC in your room can make life here a lot more comfortable. The unit still works great, only reason I'm selling it is that I'm leaving the area and am not able to take it with me.

Let me know if you're interested.