Elgato has released Thunderbolt Dock that adds extra ports by connecting a single port to the back of any Mac. It is a must-have and a very useful accessory for Macbook Air users which is really scarce on the ports-end.
Thunderbolt Dock from Elgato includes 9 ports and one more for 12V power adapter. There are a dedicated thunderbolt port for the input and one for daisy chaining extra peripherals such as HDMI, Ethernet and 3x USB 3.0 ports.
Feature list at a glance.
connect everything to your MacBook or Ultrabook at once
two Thunderbolt ports: extended Thunderbolt versatility
built-in HDMI port: directly connect a display of your choice
built-in Gigabit Ethernet: enjoy increased network performance
three USB 3.0 ports: simultaneously connect all of your devices
separate microphone input and audio output
An alternative to this is Belkin Thunderbolt Express dock which we also gave a thumbs up. However, that one comes with an HDMI instead of FireWire 800.