MWave has the Premiertek ANT-9dBi 802.11b/g/n 2.4GHz 9dBi SMA OMNI-Directional High-Gain Screw-On Swivel Antenna for Routers or Network Card Adapters for $5.49 with free shipping. Can boost wireless signal from a standard 2dBi to 9dBi.
You can read my comments on this item at mwave. I would call this more of a 6 db antenna. It -can- work to boost signal in the plane perpendicular to the antenna, but it does that by stealing signal from the "top' and "bottom". That may not work in all cases (it does in mine, so I'm happy). I saw signal go from almost nothing to actually usable over a 100' range (with antennas on both the access point and the USB adapter). One end alone did not cut it (what good is talking if you can't hear?).
I think this is good for scratching my back.
I got one of these. No effect on range.
I just took the pair I have off the router two days ago and put the three inch stock ones back on. I don't think these made much difference if any.
No gain seen with this antenna.
You can read my comments on this item at mwave. I would call this more of a 6 db antenna. It -can- work to boost signal in the plane perpendicular to the antenna, but it does that by stealing signal from the "top' and "bottom". That may not work in all cases (it does in mine, so I'm happy). I saw signal go from almost nothing to actually usable over a 100' range (with antennas on both the access point and the USB adapter). One end alone did not cut it (what good is talking if you can't hear?).