Even the most impressive stereo setup today feels woefully obsolete if it's trapped in the pre-wireless age. After all, a fair number of us rely almost completely on streaming services and a combination of our smartphones and laptops, and swapping them in and out of a setup just isn't great. But you don't have to trade in your prized vintage hi-fi for a newfangled one with built-in wireless capabilities yet: Plug the Harman Kardon BTA 10 into the receiver and you'll be able to stream Bluetooth 4.0 (BT4) audio from any paired Bluetooth device (range depends on your abode's building materials and layout; in our plaster-walled building we could comfortably sit 20 or 30 feet away, but not once we threw a wall or two in the way). It's a no-muss, no fuss Band-Aid solution in the best sense of the word, and the tiny receiver – a little bigger than two stacked, oversize matchbooks – neatly tucks away behind your system out of view. [$59; harmankardon.com]