Uhhh... yes, it DOES need a server. Timbuktu is simply a client and a server all in one software package -- it's not like you could use Timbuktu to connect to a computer that didn't have the Timbuktu software package (or some sort of VNC/remote control software) installed on it... when you install Timbuktu, you're most definitely installing a server software package.
Besides, Timbuktu is commercial software. You can do this for free with VNC.