Yup,you sure can!.
If you want to live "contract free" check out the prepaid cellular phone company Virgin Mobile.
The offer whats called the MiFi . Link >>>
http://www.virginmobileusa.com/mobile-broadband/mifi-2200.html
I think the price is $45.00 per month (but again...no contracts, so if you can't pay....there are no penalties ....or if you simply want it handy so WHEN you do plan to take a trip, all you have to do is put the money on the account and BAM you have internet and without being stuck in a contract).
My parents use it and they like it, its pretty fast too! you can watch youtube videos ,use netflix on it,downloads speeds and upload speeds are fast.
its about the size of a credit card . It a mobile wifi....and will send internet to up to 5 devices that are wifi compatible simultaneously.
its battery powered so you can slip it in your shirt pocket and have internet on you. or you can plug it into a wall outlet and set it on a shelf....it also comes with a USB cord so you can directly plug it into your computer for internet (incase you do not have on your computer).
there are other options too of course like a sprint or verizon USB air card or and aircard thats inserted into a Port on your laptop.....but most of those require a contract...and if you have less then perfect credit you may have to pay a deposit on top of it all.
you can also get phones now, some prepaid phones....such as some of the prepaid virgin mobile LG phones now have built in hotspots (basically the same thing as the MiFi I mentioned above but it doubles as a cell phone) and I THINK they offer a $25.00 unlimited plan also!!! so $25.00 would give you unlimited phone calls, text,picture mail,internet on your phone AND would emit WiFi signal being that it is a mobile hot spot.
also there are phones like the sprint EVO which do the same thing basically BUT the phone plans normally run a minimum of $80.00 AND you have to be stuck in a contract.
anyhow, those are a few options...hope that helps