Hey guys!
I wonder if I can create a directional link with these cheaps wireless transmitters.
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=270755096487&ssPageName=STRK:MEWNX:IT
Usually they operate in the surrounding area, I would like the transmission would be directional. Is it possible?
Thanks 
To make the radio signal directional you will need a directional antenna. Those modules don't seem to have a provision for an external antenna but you should be able to put one at the focus of a parabolic dish or in the "driver" position of a Yagi antenna designed for the right frequency. This will make them considerably larger but more directional.
The bigger the parabolic dish the more directional they will be.
I saw a lot of 2.4GHz (wi-fi) directional antennas. Would it work?