My poor understanding of 3G is that it’s like WiFi only with a wider range (like a cellphone network). I know that 3G SIM cards exist for cell phones. Do they exist for netbooks as well, or are netbooks permenantly tied to one network? Is there any way to get a pay-as-you-go thing, like you can with SIM cards for cell phones? Is this a stupidly ignorant question?
Netbooks don’t usually come as standard with a built-in SIM card so no worries about them being linked to only one network. A foreign-bought netbook should have no trouble connecting to 3G in the US because the 3G card will be provided by a US provider.
You probably need to read up on Mobile Broadband.
Virgin has a Pay-As-You-Go mobile 3G deal.
“3G” generally refers to cellphone data networks.
Remember that ‘3G’ is a nebulous term in the US and Canada. There are two competing incompatible standards that are marketed as ‘3G’. AT&T and Rogers and others use the 3G standard in the GSM family, and have SIM cards. Verizon and Bell Canada* and others use the 3G standard descended from Qualcomm’s CDMA systems. These do not have SIM cards unles they are roaming on GSM networks overseas.
Add to this that all systems use different frequencies** in the US than overseas, and some, such as T-Mobile, place their 3G network on a completely different frequency*** that isn’t compatible with anything else in the States…
You need to know exactly what you have: what standards it uses and frequency bands it works on. Post that and the model number here and I’m sure Dopers will be able to tell you what systems it might work on.
Yes, it’s confusing. And that’s not just because I might be explaining it badly; it is inherently confusing. I used to work with this stuff: I know.
[sub]*Bell Canada and Telus just completed a 3G GSM overlay of their 2G and 3G CDMA networks. Now they have the iPhone too.
**Regular 2G uses 1900 and 800 MHz in Canada and the States and 900 and 1800 MHz overseas; this is used by both CDMA and GSM systems. The 3G versions also use 2100 MHz I think in the States and Canada; I believe that’s the main 3G frequency overseas.
*** T-Mobile and Wind use 1700 MHz and 2100 MHz in the US and Canada. So no iPhone for them. Yet.[/sub]
I’ll split the answer to answer the different parts of the question
First if the question is whether or not Net books come with a built in 3G Modem, the answer is yes, though it is not standard. Some Higher end Netbooks (Like the Sony P series) do have them as standard but they are the exception to the rule. Many Notebook manufacturers like Dell and Lenovo do offer the option to add a 3G modem, and many come with antenna pre installed just in case you decide to add it.
Also, some netbooks with a internal modem, if bough subsidized may have the modem locked to a specific network so may require unlocking it before you can pop in your own sim.
Now the main question, whether a Netbook / Notebook with a 3G modem Purchased outside the US will work in the US and provide 3G service, the answer is It depends.
To understand why that is you need to understand that 3G is generic term for next generation voice and data communication. Different countries have allocated different frequencies to cell phone providers for providing this service. So while the technology is the same, equipment from one country may not support the frequency bands used in another.
Nowadays, the split is largely between the US and the rest of the world with the US using 1900Mh & 850 Mhz (At&T), 1700mhz & 2100Mhz (T-mobile) and most of the rest of the world using 1800MHz & 2100hz. as such if a device does not support the correct frequency it will not work.
Now, Many of the newer Internal Modems do support most GSM bands and some also support CDMA as well (Gobi). The only way you can know is to check the name of the company that manufactures the 3G modem or check the manual for the computer where they will usually state which bands are supported.
Ugh, it seems a lot more complicated than I thought it would be. For some reason I was expecting it to be similar to a cellphone, where you can just pop in a SIM card and it would automatically connect to a network and you could just pay as you go.
$100 dollars is a lot to spend on a doo-dad I’m only going to use for a month.
I think I’ll just try to stick to Wii-Fii hotspots and such. :smack: Thanks, everyone, for taking the time to answer. 
Well, it is similar to a cellphone. Cellphones have the same complexities, because they use the same networks.
It is a lot simpler. While the two posters after me are 100% accurate in what they have said, I don’t feel that the information is relevant “practically” to your question.
If you have a netbook that you bought outside of the US it is very unlikely that you have a pre-installed SIM card. All you need to do is exactly what you said. You pop a SIM card into the laptop and you connect to the 'net, paying as you go.
The only problem though is that you have to buy the 3G modem that the SIM card goes into. This is where the $100 charge is coming from.
Verizon only charge $50 for 1 months access (capped) but I don’t know how much the USB 3G modem will cost.