Um, let me correct what "Mike" has said. The current Mobile Broadband plans from Verizon Wireless are as follows:
$39.99 for 250 MegaBytes of total data each month, with an overage rate of $0.10 per MB
or
$59.99 for 5 GigaBytes of total data each month, with an overage rate of $0.05 per MB
The overage rates on these plans was significantly discounted recently. You can see the actual plan details (including usage estimates for most popular applications) at the Verizon Wireless dot com page (hover your mouse pointer over the red PLANS button at the top, and when the dropdown menu appears click on the Mobile Broadband selection),
Oh, and Mike makes a good point about not leaving the connection active when you are not using it, as Windows and other applications can initiate data download/upload activity that would be billed as legitimate usage.
But there is no truth whatsoever to the idea that it won't do video. If you are in a Broadband coverage area, the 3G connection to EVDO should provide download throughput speeds averaging from 600 to 800 kbp. Which is plenty fast enough to support streaming video. Just remember that streaming video, file download/upload activity and online gaming are the quickest ways to run through your monthly data allowance.
You can track your data usage (like monitoring the odometer on your car) either with the VZAccess Manager software that you connect with, or at Verizon Wireless dot com by signing up for your personal "My Verizon" access on the website.
Oh, and to the original poster, there is no such thing as "hidden fees", or you'd see all companies in court much more often. All fees that Verizon could charge are listed at the page I cited above for all the world to see. The only reason they would be "hidden" would be if the purchaser just didn't read the plan details.