For those that live in Seattle/Bellevue areas Vetco now has several types of NEW IN BOX 2.4GHZ antennas, Both onmi and directional. (surplus inventory from intermec)
I picked up a 2.4 GHZ 13db Yagi last night for $69 +tax. (After opening the plastic antenna housing tube I feel it would be VERY easy to duplicate it for personal experimentation!) The yagi itself has been stamped cut from sheet metal and the feed point is just an etched PCB with a short RG58A/U cable pigtail soldered to it and terminated with an "N" connector.
"Advanced cable" down the road can custom make most types of adapter cables. They have RP-SMA connectors.
Gosh I love this city!