We just moved into our new apartment and due to the delay in transitioning Internet services found ourselves without Wi-Fi to the web. My Cradlepoint CTR35 hooked up to my Verizon 4G Pantech modem filled the gap nicely. To maintain router continuity with existing port forwarding and SSID references (we didn't want to switch to the 4G/Cradlepoint via its own hotspot name), I hooked the Cradlepoint router up the usual wireless one via the pictured ethernet hub. I also used it to route our Vonage service and thus now have the entire house and all networking devices working off 4G. It's fast enough that it can actually do the job until we get real broadband from the cable company.
Of course we have to be careful not to exceed my monthly cap on the 4G plan, but I'm watching that on a little Verizon Wireless dashboard graph each day and taking advantage of alert features that should warn us when we approach a particular threshold. We have a standing rule to avoid You Tube videos while this infrastructure is in affect. Imagine the day all Internet service is metered; these are the things we'll start thinking about. :/