Dell Home offers the Netgear Push2TV 1080p Intel Wireless Display Adapter, model no. PTV2000-100NAS, for $49.99. This $20 mail-in rebate cuts it to $29.99. (Amazon charges the same via this rebate). With free shipping, that's the lowest total price we could find by $20, although we saw it for $5 a week ago (since expired). This adapter wirelessly transmits whatever is displayed on your laptop screen to your TV, up to 1080p. Rebate expires June 30.
Note that this device requires a system with Intel Wireless Display (WiDi); click here for more information.