Ever need just a little bit of broadband? Virgin Mobile's BroadBand2Go modem and plan is a good idea for the occasional mobile Internet user, whether you're a small business owner who needs to hit the Net outside the office or a family going on vacation who wants to surf a few Web pages while out of town. Virgin's pricing plan doesn't make sense for heavier users, though.

Virgin Mobile resells Sprint's nationwide EVDO 3G broadband service with their own flexible payment plan: you buy your broadband by the bit. Plunk down $10 and you get 100 MB. $20 nabs you 250 MB. Forty bucks garners 600 MB, and if you commit $60, that's a gig. There's one catch, though: your data allowance expires, usually after 30 days.

Now you may suddenly complain, "but $60 gets me five gigs on Sprint!" and that's true. But that's a big buffet where you leave steak on the table after you're full. Here, you can pay for exactly what you use. When you run out of MB, you can buy top-up cards (even with cash) at local stores, or buy megabytes with a credit card on Virgin Mobile's Web site.

For light users, this can be very economical. In five hours of remote working, I consumed about 100 MB of data. (Our PCMag.com home page is about half a meg.) That's $8-10 or so. Now, note that I wasn't doing any media streaming—no YouTube, iTunes, Pandora or anything like that. That would have totally nuked my MB allowance. When I say "light users," I mean it.

The closest occasional use plan in wireless broadband is Verizon's "day pass" plan, which offers unlimited use for a day for $15. Verizon also charges $120 more for the same modem Virgin uses, without a contract.

Virgin's plan works with the Novatel Ovation U760 modem, which I tested on Sprint earlier this year. It has an external antenna jack and an extremely slow MicroSD card reader built in. For now, Virgin's version of the modem only works on Windows PCs, not Macs or Linux machines.

Plugging the modem into both Windows XP and Vista machines automatically launched the installer. Virgin's connection manager shows the amount of data you've transferred in the current session. When you connect, it automatically launches your browser on Virgin's account summary screen, which shows you the megabytes you have remaining and gives you options to buy more.

I got surprisingly slow results with Virgin's modem, but it may have just been a very bad day for Sprint's network (I've seen similarly bad days before, on all the carriers). When I tested the U760 with Sprint earlier this year, I got an average of 1.15 Mbps down and 419 Kbps up, with download peaks of 2.45 Mbps and upload peaks of 702 Kbps.

Testing the Virgin Mobile version over two days in three cities in New York and New Jersey, I got an average of 599 Kbps down and 253 Kbps up, with downloads peaking at 1.37 Mbps and uploads peaking at 679 Kbps.

I can see plenty of uses for this $149.99 modem and its infinitely flexible data plans. If you're a very occasional wireless broadband user, or you want to buy your megabytes with cash, Virgin Mobile Broadband2Go looks like a good choice.

Heavier occasional users should look at Verizon Wireless's $15/day plan (though you need to factor in Verizon's $269.99 modem price) or Cricket Wireless' $40/month plan, if you're lucky enough to be in a city that Cricket covers.

More Cellular Card Reviews: