After seeing the freeantennas for wireless Internet to extend the router's range, I tried a quick and dirty homebrew reflector using an auto oil funnel (soft cardboaard) and affixing half of its side with foil aluminum. Well, my marginal signal (was almost non-existent at night, for some reason) is now "Very Good" according to the [usually overly optimistic] X-Micro's 11b software.
However, I noticed that the angle and placement of the reflector and the USB dongle (hope that's the right term for the transmitter on the laptop) is very critical. Off by one inch, and there is no signal.
If there is a contest for making the most practical, cheapest dongle antenna, this is my entry. The advantage of a soft cup is its flexibility, portability. I am going to cancel my thoughts of buying a ready-made antenna.