mwave offers the Premiertek 802.11n 9dBi Screw-On Antenna, model no. ANT-9dBi, for $4.99 with free shipping. That's tied with our mention from a month ago and the lowest total price we could find by $8. This antenna purportedly increases wireless signal strength from 2dBi to 9dBi. It screws directly onto a router or network adapter.