If you use a lot of USB devices (heck, two) with a MacBook Air, a hub is a necessity. The MBA has a single USB port which can give fits to people that need more. The problems with hubs is that they can be bulky and some require a separate power supply.
If you're looking for a svelte little hub that gives you three powered USB 2.0 ports check out Dr. Bott's T3 USB 2.0 hub. It retails for US$20, comes in silver and white and seems to be sold out a lot. The silver model (pictured) is the perfect complement to the MacBook Air and just fits into the MBA's snug, recessed USB 2.0 port.
|Image Gallery: I've created a gallery of photographs of the Dr. Bott T3 USB 2.0 hub.|
The best part about the T3 is that it's powered:
A USB hub without power supply will typically refuse to provide power to any device that requires more than 100mA current. USB floppy, SuperDisk, ZIP drive, some USB flash drives and most USB ISDN adapters fit into this category. Typically, these devices do not function when connected to the USB keyboard, which contains a non-powered USB hub.
By contrast, T3Hub will report itself as a self-powered hub, so that it can accept devices that have a nominal power requirement of 500 mA. As nominal power is rarely used in full, it usually is no problem to drive additional devices (mice, keyboards etc.) alongside one power-hungry USB device. If this ever should result in too much power consumption, the T3Hub will shut down automatically and the computer reports an error.
The special thing about T3Hub is its capability to host two normal low-power USB devices and one high-power USB device - all without requiring a power supply itself.
One thing that did not work while connected to the T3 hub is the MacBook Air external SuperDrive. It only works when connected directly to the MBA USB port and won't work with any USB hub, so this isn't a limitation of the T3.
More pictures are in this gallery.