Well a few weeks ago the Raspberry pi Foundation surprised the world by not only releasing a very small raspberry pi called the Pi Zero, but at a price point of £4 /$5 in the UK /USA. And if that wasn't enough they gave 10000 of them away free with the official magazine, MagPi.
I was one of those lucky enough to get hold of a few copys of the magazine for me and my makerspace and thus the Pi Zero. As this board only has 1 micro USB port for peripherals and a Mini HDMI port for video out it was a couple of days before I could test it after getting hold of the converters. Once these arrived (cost about £3-4 for the pair on ebay) I was able to hook up the Zero to my lap dock.
I loaded the Micro sd card with the latest Raspbian Jessie image, plugged it into the dock and away we went. The Pi Zero is factory clocked at 1GHz and has 512mb RAM so is on a par with the raspberry pi B+ and performance wise it compares well.
However this tiny PC will for most folk not be used for day to day PC tasks it's size 65 x 30 x 5 mm, unpopulated 40 pin GPIO and 9 grams in weight, will mean that at this price most of these boards are destined to be used in embedded projects where the lack of connectivity will be a positive not a negative, as you are able to add only the nessesary conections for your project.
As it is fully compatible with the other Raspberry Pi's you can programme the card with a B+ or Pi2 and test out everything prior to putting the Zero in whatever project it will run.
If your into programming and electronics and have been using previous Raspberry Pi Boards then at $5/£4 this is a must buy bit of kit, if you can get your hands on it. The original stock of both the magazine and those available through outlets such as The Pi Hut, Pi Supply and Pimoroni all sold out within a day or so of release. With manufacturing beeing about 2000 units a day it will be a while before supply exceeds demand.