If it is just browsing you're after, then I use an Android app call "3G mobile network" that turns my phone into a wifi connection for my laptop and tablet. As the internet facility is bundled into my phone package, I don't pay for anything while browsing, and others can connect to my phone to get a connection too. It is by far the simplest and cheapest method as it is quick, I always have my phone on me anyway, and I don't have anything else to set up or install.
I believe recently the a similar app was released for iPhones