"I'm thinking about one of those external cards you put into your laptop (like from Verizon) that gives you Internet access no matter where you are."
You've been misinformed. Or, deluded by Verizon's marketing
department, who sometimes have been known to live in an alternate reality.
There is no magic card that gets you access from anywhere. You've got a choice between laptop cellular cards, and laptop WiFi cards. The cellular cards only work in one carrier's cellular data network, which typically is the same as their regular coverage in major cities. In airports, you've probably seen WiFi. Carriers like T-Mobile will sell you weekly/monthly/annual access for their WiFi nodes. (T-Mobile has a national network of WiFi hot spots in places like airports and coffee shops.)
And in some airports including FLL, the authorities simply provide free WiFi access to anyone who wants to use it, as an incentive to use their airport
. (Unlike Logan, where the airport
was trying to shut down private WiFi hubs in airline clubs, so they could sell it themselves.)
...well...the "S" HTTPS stands for "secure" and once you reach that web page, in theory everything is encrypted both ways. That still leaves your computer with no protection for the connection itself--and you open to hacking. You MUST run a firewall (free in XP and Vista, or free ZoneAlarm, etc.) or you will be hacked. It takes only a few minutes for someone to plant a trojan on your computer and hijack it if you are connected to any WiFi network without a firewall, and there are folks who hang out at the airport for just that purpose.
Even if the WiFi spot uses WEP encryption and gives (sells) you the access key to that, WEP can be hacked in under five minutes.
The cellular data networks, as far as I've heard, are more secure. You can still be hacked--but only in the same ways that you can be hacked over a wired network.
Next year Sprint and another carrier are deploying WiMax, which is sort of "WiFi on steroids" with the range of cellular data systems. Next year.
For more protection, you really need to be using WPA access (encryption that works well) to a WiFi router, or the cellular data card (about $60/month for unlimited plans under contract
and that's cheap
compared to their "pay as you go" plans), or you can use what is called "VPN" Virtual Private Network software
, which sets up a secured connection between your computer and a VPN server, so anything that you broadcast is encrypted and dropped at that server, where it enters the internet out of reach of most eyes.
VPN requires that you are dialing into your own VPN server (i.e. corporate) or using a subscription service