What do u mean gb? Aren't you taking the signal from the phone? So shouldn't the 3G be unlimited just like it is on your phone?
Please tell me you're joking. As much as you post on this website and parade around screaming how the iPhone is the greatest thing ever invented by man and that no other phone can "beat it", and you haven't read a single media release or thread about data usage caps, throttling and grandfathered unlimited plans? I mean, i would hazard to guess that outside of new Apple product releases, one of the top 5 topics of iPhone communities like this one is data usage of this sort...meaning that the amount of topics relating to internet tethering and data usage has to AT LEAST top 30-40% of the discussed subject matter on any of the iPhone forums...and some how you're completely in the dark about this? lol.
Unlimited data packages are going the way of the dinosaurs...AT&T hasn't had them for some time, Verizon followed suit shortly after, and now that Sprint has the iPhone, you can already see their plans shifting with like frequency...the iPhone user community simply uses A LOT more data than any other phone, and because of this, the carriers know they can make money by capping the usage and charging for "extra" data.
AT&T offers 4GB at $45 for a data plan...that includes the old standard $30 iPhone data plan + $15 for data tethering service PER MONTH...i think there is a plan for 2GB, 1GB and 200MB...but you'd have to go google what the pricing for those is. Verizon and Sprint have their own pricing scale, but in the end, to have an iPhone and data tethering, you end up spending about the same amount per month over all regardless of what carrier you use.
You do basically have access to USE an unlimited amount of data through tethering or on the iPhone itself, but it's not free...you will pay for your initial data plan...and you will pay extra the more data you use...some people who have had iPhones for many years are grandfathered into unlimited data plans, and some of them never experience any kind of negative performance using as much data as they want...many of them though experience data throttling (forced slowing of speeds after a certain amount of data is used) or constant warnings from the carrier about excessive data being used (even some being forced into a tiered plan without a choice). These grandfathered accounts will all eventually see some kind of limitation, but for now...some people still enjoy worry free data usage.
With that said...let me make a suggestion to you. Instead of posting more threads with the main topic point of saying that Android phones suck and the iPhone is the best thing in the world...go spend some time in the forums reading old threads or even googling some stuff like this so you can at least say you put some effort into learning this kind of thing, because honestly, with the frequency you post random stuff on here, something tells me that you have plenty of time to know this stuff without having to have it spelled out like this.