Ditto what JohnO and others said about Verizon. We have also used the Wilson amplifier to increase the Verizon air-card range with delightful results. The amplifier boosts cell phone performance too.
See:
http://www.wilsonelectronics.com/
The amplifer difference is most noticable when we are driving. The signal is more stable so stays connected for longer periods of time. Signal drops and reconnects are reduced. For a solo driver, the booster would be of little use with an air-card since one does not drive and surf the web at the same time (let's hope!).
Wi-Fi cards are cheap and many Wi-Fi networks are free. If your laptop computer does not have Wi-Fi built in like many new ones do, you can buy a card at CompUSA, Best Buy, Circuit City, Radio Shack, Fry's and other electronics stores.
There have been times when we've been in hotels where the Verizon signal is weak. That's when the Wi-Fi card comes in handy. We've also used it as cheri1122 does, if we are needed to get online in a remote area and the Verizon signal was not available. It is noteworthy that some states now offer Wi-Fi hot spots at some rest areas.
If you are in a van, Cheri's technique is easier to use than if you are in a truck. Vans are more nimble and it is much easier to run around in a hotel cluster or retail area until you find a free hotspot. What might take a few minutes to accomplish in a van may take a half hour in a truck.
We carry two laptops in the truck because we got tired of waiting for the other to finish using the one we shared. Wi-Fi cards are great for setting up a wireless, peer-to-peer network between the two machines. I do that to back up each computer to the other. In addition to storing our backup data at home and away from the truck, one computer mirrors the other. If one breaks down we can get on the internet or into our business or personal data with the other computer without missing a beat. Wi-Fi makes it easy to keep the two machines in sync.
That technique could also be used by drivers that have a desktop computer at home and laptop in their truck. When home, it would be easy to connect the two using Wi-Fi and move backup data between them. Both machines would need a Wi-Fi card (built in or external) to do this.
I LOVE the ability to get online for an unlimited amount of time while parked away from truck stops and even while Diane drives down the road.
At the moment, we're sitting in an upscale shopping mall, parked near the delivery trucks the grocery store uses here. We spent a quiet night here with a cool breeze blowing through open sleeper windows.
If I wanted a cup of store-bought coffee, I'd walk over to Starbucks. The grocery store bathroom has signs on the door and inside about how management prides itself on clean bathrooms. They have the same chart on the wall for the attendant to initial that truck stops do. The difference is in the grocery store, the attendant actually cleans the bathroom before initialing the chart.
Here, there are no pubic-hair collections to view, no fear of trucks backing into yours while you sleep, no smell of urine and a litter-filled parking lot, and none of the other negative features that makes truck stop life so special.
That's the difference Verizon internet access makes. That quality-of-life enhancement on the road makes Verizon worth every penny we pay for the unlimited access service.
Wi-Fi has its advantages as noted above. Wi-Fi's biggest disadvantage is limited range. We have and use both Wi-Fi and Verizon. If we had to choose just one over the other, it would be Verizon.