The Hoo Too travel router, available in 3 different varieties on Amazon, has a nice feature: If you connect it to a wi-fi source intended for one device (say, the wi-fi on a plane or in a hotel room), you can then connect several devices to the Hoo Too.
This can save you substantial amounts of money during a trip. So far as the airline or hotel is concerned, you have only one computer connected to their wi-fi.
The least expensive Hoo Too travel router, the HT-TM02, has no battery and must receive power from a portable battery or other USB source. It costs only $18.99 with free Prime shipping. It weighs less than 2 ounces and is only about 2 inches x 2 inches. Think carefully before buying this one – do you really want a device that always has to be connected to an external power source to work?
For just $6 more you can get model HT-TM01 that has a battery with adequate life for most uses. That battery can also be used to re-charge your other devices, like a smartphone.
A third mode, the Titan, with pink top, has a larger battery for longer life and costs $40.