Newegg offers the ASUS 802.11n Wireless PCI Express Adapter, model no. PCE-N10, for $3.99 with free shipping via the directions below. That's $1 under our October mention, the best now by $17, and the lowest total price we've seen. It features WEP, WPA, and WPA2 encryption. Deal expires March 31. To get this deal:

1. View the ASUS 802.11n Wireless PCI Express Adapter for $21.99
2. apply coupon code "EMCEHGN63" to drop the price to $13.99
3. redeem this $10 mail-in rebate for a final price of $3.99