Newegg offers the TP-Link WiFi Smart Plug, model no. HS100, for $29.94. Coupon code "EMCEGGH69" cuts it to $19.94. With free shipping, that's the lowest total price we could find by $9. It can be controlled via a smartphone and features scheduled on/off and away modes, 802.11n wireless, and voice control via the Amazon Echo (sold separately). Coupon ends February 29.