A system for allowing all the devices on me to mount each other's storage seamless and make use of each other's various radios.
It drives me cray that I can have a phone with a 4G antenna, a laptop with wireless, and a kindle all three speaking bluetooth, and yet they don't transparently for my 'personal lan'.
apple products do this - but you have to go all apple. It's pretty cool - when my phone rings and I'm typing on my mac, my mac starts ringing - so I can answer the phone on my mac. Same with texting when I 'm using my mac. Same thing happens with my iPad too, but I don't use that as much. I can play movies on my apple tv to from any of my devices. Same with phone 4g using from your mac when you're out and so on. It's a bit magical, but as always, the cost is your soul :-)
Edit: why the down vote? not my fault that's how things work.
It drives me cray that I can have a phone with a 4G antenna, a laptop with wireless, and a kindle all three speaking bluetooth, and yet they don't transparently for my 'personal lan'.