If you do not have more than an intermittent need for using your laptop in the absence of a Wifi hotspot, I would recommend going to the Android store and downloading PDAnet. It is a great tethering method, and it is free - you’ll need to install the companion part on your laptop, but you can do that from the SD card in your phone if you’re away from an internet connection (it walks you through the steps).
If you frequently use your laptop in areas where wifi is not available, then I would pursue a usb laptop card dedicated to internet access. I don’t believe in dumping that many services onto my phone regularly - it is, afterall, a phone. You can get service for $20 to $40 bucks a month and you can add through your cell provider or pick up one at Wal Mart with a pre-paid plan.
I agree that if it's a temporary need you should just tether your laptop to your phone, assuming (i) you have a data plan on your phone, (ii) your carrier allows tethering, (iii) your laptop has wireless capability, and (iv) your phone can get a decent signal where you need to use it. You will need to keep your phone plugged in, though, because a tethered phone depletes the battery in a hurry. I recommend the Foxfi tethering app, which is free, simple to set up and use and requires nothing to be installed on the laptop.
If you need a more regular solution, the MIFI 4620L is a killer unit.