Here, I'll tell you how to get and reacharge a data SIM with about 1gb of data for 10USD. This more than suited my purposes for communication in Taiwan, with more than enough room leftover for online calls, mapping, searching places to eat or things to do, and other basic browsing activities.
TIP: Receiving calls is free, or at least extremely cheap. If you're a bum, have people call you, particularly if they're on unlimited minute plans anyway (every Taiwanese person you meet).
Get the SIM
First, have a GSM unlocked phone, or GSM unlock your phone. This will allow you to use a foreign SIM card in your phone.
Then, go to a FarEastone (遠傳電信股份有限公司 or just 遠傳) store. Bring your passport. Find an English-speaking rep, and ask for a "pre-paid" data SIM. They will give you several options, just choose the ~500NT prepaid phone. Clarify that the SIM they're giving you can be recharged at 7/11. Stick the SIM in your phone, follow activation instructions they give you, and you now have call and text.
If you call 777, you can listen for a while to find the English option. Once you select this, the robot will always speak English when you dial 777. The way to change to English changed too much for me to accurately record it, so you'll have to find it on your own.
In short, to add a data plan to your phone, dial 777, press 5, enter your birthday in year/month/day format such as 19780203 for a birthday of February 3, 1978. They will give you several very stupid data plans, such as 20 MB for 200 NT. Press 1, then 2, to go with the 1gb plan for 300NT.
300NT will be taken from the available funds on your pre-paid account. Once it's spent, it's locked down. You can use up all the rest of the funds on texts and your internet will keep working until you use 1gb or 30 days passes.
You will have 1gb of data to use for 30 days. After 30 days, your data will cost some absurd amount and drain your remaining pre-paid funds instantly. Ensure to call back and refresh your plan every 29 days.
Recharge Your Pre-paid Account
You'll know you're running out of money for calls and texts by a voice message stating so either in English or Chinese every time you make a call.
To recharge, go to any 7/11. There'll be a small kiosk near their copy/print machine. Follow the visual instructions to get a receipt that you'll later take to the counter:
|Press the little orange button with a picture of money.|
|Press the red button on the right. It means "agree," basically.|
|Make sure to press the correct "1F" button, the one without the red text. For future reference, that's the FarEasTone alternative logo.|
|Press the far right red button, after ensuring you're only buying one recharge thing.|
|Take this receipt to the checkout.|
Call 777, listen for the "charge phone" option, and follow instructions. I believe it was 2 last I checked, but double check.
They'll ask for that long PIN number on your receipt. Input it as per instructions.
Boom, you now have however much money you bought on your phone's balance. Call and text at your whim.