Inland Pro 7-port USB Hub
This one's versatile for regular home use or travel. It's slightly larger than the Targus Travel Stick – longer and wider, but thinner – with three more ports, supports the same USB 2.0 throughput, and resolves the one caveat of the other adapter – it has a dedicated USB power supply. Now you can run your USB-powered devices without fear of problems. On the other hand, the USB cable and power cable disconnect to keep the device slim, but requires a bit of cable management for the frequent traveler.
The aluminum casing and activity LEDs are nice cosmetic touches, and overall it's a great device for around $15. All the necessary parts fit in a Ziploc bag, though it isn't as fit and trip for nomads as the Travel Stick is.
TrendNET 54Mbps Wireless G USB 2.0 Adapter
Why in this age of everything coming standard with wireless would you need an adapter like this? Because things break. If you're traveling with your laptop and your system suggests a wireless driver update for your built-in hardware that causes it to stop working correctly, how will you get back to the Internet to get the correct driver and resolve the problem? Or say you drop the laptop and everything still works except your wi-fi. Or you have a desktop computer that you want to move to another room without running wires behind the walls or looking for other more expensive solutions. That's where a versatile adapter like this comes in handy.
Plug it in, install the software, and you're up and running. It's about the size of a slightly thicker, wider USB flash drive, with a cap that flips up, protecting the USB connector when in storage. If your USB ports are so close together that plugging in the wi-fi adapter would block the adjacent port, it comes with an extender/adapter that adds a couple of inches to the connecting end, slimming down the connecting end to standard USB size. The adapter is also semi-rigid, meaning you can plug it in, then bend the cable and it will stay in place, pointing the adapter up, down, away from you – whatever you like.