2 external monitors on macbook pro

So i currently have a 2009 macbook pro. I have a external monitor that im using the displayport.

i want to connect another monitor, and am looking at a usb to Video adapter,

The only problem is im tight on money and dont want to spend like $50 bucks on an adapter so does anyone have ideas or a product that will allow the second monitor without having to pay more that $25,

Thanks for the help in advance

I don't see any way that would be possible.