What do you think: would it be infeasible or near-infeasible to interface with a usb wifi dongle from an atmega or whatever your favourite uC might be?
I think that it would be awesome to just add a usb port to your pcb / breadboard, plug in a cheap dongle (< 5 eur / usd), and have a connection. I know, there are things like xbee. Way too expensive I think. And there are those 433.92MHz (I don't know the name of the US equivalent) radios. Cheap, at least the ones from China, but not reliable (again, the ones from China). And such things require additional hardware to connect to your pc/mobile devices as well. Not very elegant. But on the other hand, everyone has a wifi infrastructure at home, right? Access points (which cost next to nothing), tablets, mobile phones, etc.
So, I believe that if it is feasible to create something like this, it is a lot of work. Being an USB host, talking to wifi dongle, speaking 802.11, tcp/ip, etc. But most (if not all) of those things are already open source, for different platforms though.
So, what do you think?
PS. And yes, I know that there are wifi modules ready for uC usage. They cost 10x the time of a single wifi dongle.