These days, you don’t have to travel far to find wireless access. But some hotspots carry steep prices, and you can’t count on finding one when you need it.

So, if you need Internet access everywhere, try cellular service.

All major cellular providers offer Internet cards for your lap-top. They slide into a PCMCIA or PC slot, much like a Wi-Fi card. The cards give you Internet access anywhere you have cellular coverage. The concept is simple, but deciphering the pricing and technical details can be confusing. These days, cellular providers tout broadband-like speeds. Certainly, the cards are far faster than dial-up. They fall short, however, when compared to cable and DSL speeds. Some networks are faster than others, so it helps to understand the differences.

First, there is EDGE (Enhanced Data Rates for Global Evolution). It offers speeds of 216 Kbps for both downloads and uploads. This falls shy of the 256 kilobits per second (Kbps) promised by a low-end DSL plan. EV-DO (Evolution-Data Optimized) is more advanced. The average download speed is between 400 and 700 Kbps. Upload speeds average 300 to 400 Kbps. Still, it doesn’t compare to cable broadband’s average download speed of 7 megabits per second (Mbps). You may also encounter HSDPA (High-Speed Downlink Packet Access). This isn’t common. Its download speed is 3.6 Mbps, which truly compares to broadband. HSDPA’s uploads average 384 Kbps.

Laptop cards generally cost about $200, but you can get steep discounts when you sign up for a one- or two-year agreement. I recommend that you stick with your current provider. Billing will be simplified, and you may qualify for additional incentives.

Now, let’s look at which providers offer which services and how much they charge. Sprint offers EV-DO laptop cards. For $60 per month, you’ll get unlimited access to the Internet from your laptop. Depending on coverage, the card may revert to a slower network.

Verizon also uses EV-DO technology with its BroadbandAccess service. Unlimited data usage runs $80 per month. When the service isn’t available, the card uses Verizon’s NationalAccess service. This provides download speeds of 60 to 80 Kbps with bursts up to 144 Kbps.

T-Mobile’s laptop cards use EDGE. For $50 per month, you’ll get unlimited data access. You’ll also get unlimited access at T-Mobile’s thousands of hotspots.

Cingular cards can use an EDGE network. They can also access Cingular’s HSDPA network, where it is available. Cingular’s plans are more complicated than those offered by other providers. You can purchase plans that offer limited data access. You can also purchase plans that include access to wireless hotspots across the country.

For example, a plan including unlimited data and access to hotspots runs $100 monthly. An unlimited plan without Wi-Fi access runs $80. If you already have a $40 or higher voice plan, you pay $60.

A wireless laptop card will provide you with greater mobility. You can work from the road or the local coffee shop. But it isn’t a magic bullet — just as you experience dropped calls, you could run into problems with cellular Internet access. p