The MiFi device by Novatel, has received a lot of recognition and indeed, similar to what Kleenex is to paper tissues, is what most people call a mobile broadband device. However, there are other brands out there. The Huwawei E585 does the same thing (and actually has a display screen so you can see signal strength while the MiFi does not) and costs much less. Here is an image and specs of the Huwawei and MiFi by Novatel so you can see for yourself
http://www.cellularabroad.com/mifihotspots.php