Just to point out - of those hundreds of USB based KVM switches available (including the one linked above), they all still use the standard vga monitor cable for video which must be plugged into the video card, not the usb port.
What you're looking to do, a KVM switch would be a waste of money, because those are designed to hook multiple computers up to one keyboard, monitor, and mouse. Instead, how about just a simple usb hub? There are wireless usb keyboard/mouse combos & I think you can get usb ethernet stuff.
You're not going to get away with usb video, though, so you're always going to have to plug the monitor directly into your laptop. You can reduce it down to two, depending if you can find usb wireless ethernet or not.