How do you get gigabit per second over the air?

This question is still keeping my awake during the night.

• Multiple bits per symbol is a given; there is simply no technology out there that can digitize at gigasample per second.
• Multiple antenna - how do you pack up to four antenna to a device? I can picture that being possible on a decent sized laptop, at 5GHz or more, over short distance with a favourable channel.
• Getting gigabits to the home. This becomes a question of what type of infrastructure is required to do just that. Fiber to the home, and a wireless access point (femtocell). A cell tower managing hundreds of gigabits of data over the air will be challenging.
• A lot has to take place, similar to idea of fuel cell vehicles. Infrastructure is a significant issue.