The ZTE 288C should work well in areas with Verizon coverage. It is in the box with the RED map on it. Currently $49 at Walmart.
The ZTE 289L is on AT&T and has a BLUE map on the box. That one DOES NOT WORK. :M I had one and returned it. No matter where you are in the country the AT&T units go through a proxy server in Florida and slow down on sites not associated with Google. There is a fix for that problem but it requires that you change your computer to have a MTU of 1450 rather than the normal 1500. If you don't understand MTU than that is not the hotspot to buy.
edit: There is an old thread about these hotspots but I can't find it at the moment.
edit2: see update/correction
HERE