I looked for a DTAC booth to buy extra credits so I can connect to the Internet. The lady at the counter suggested I just buy the Happy Tourist sim that provides unlimited 3G access for 7 days and THB 100 load credits. Knowing that I would probably be out sightseeing most of the time in the next five days, I bought the new sim.
I inserted it in a Samsung Galaxy Y phone and used that as my mobile hotspot. When the data packet is on, I can connect my laptop, Windows Phone, and iPad mini to the internet as well. The catch though is that the Samsung phone's battery drains faster when WiFi is on so I made use of a power bank to make sure my hotspot doesn't die on me.