Yes, I meant to embed links in my post.
With the ipad or macbook, you can (of course) plug in regular headphones. However, if they have Bluetooth, you can use Bluetooth enabled headphones and be (somewhat) free of cables - at least those running to the device. There's nothing more to buy. Enable Bluetooth on your device, sync it, and you're good to go. However, do keep in mind that using Bluetooth will be a bit more of a drain on your battery than if you just plugged in headphones directly.
I like the Sony ones as they allow the freedom for you to choose whatever headphones you like to use. Many other brands/models are an "all in one" unit where you cannot change the headphones.
As for the example about using RF headphones hooked up to a TV, most flatscreen TVs in hotels these days have the necessary outputs (usually RCA plugs) to hook those up. And, most headphones include those RCA cables. If not, it's a quick trip to your local dollar store. The only time I found where I couldn't hook up my cables to a flatscreen TV was when it was flush-mounted to a wall. I just couldn't physically get to the back.
Now, if you want to get really fancy, you could hook up your Bluetooth headphones to your macbook and output HDMI to the flatscreen. Turn down the flatscreen to "0" volume and listen to the audio output via the headphones. Of course, I don't know if this will work for all models of laptops so it's best you test it out at home before trying it on the road.