Reddit reviews PowerBright Step Up & Down Transformer, Power ON/Off Switch, Can be Used in 110 Volt Countries and 220 Volt Countries, Convert from 220-240 Volt to 110-120 Volt & from 110-120 Volt to 220-240 (2000W)

If you get a smaller kettle or a kettle with a high wattage (1500w is a good choice) then it will boil a bit more rapidly than your average kettle.

There is another way to get a rapid boil kettle that is literally more than twice as fast to boil as normal kettles. I have one but it's not a cheap option.

First, buy a kettle designed to be sold in the Chinese market or other overseas country where the standard outlet voltage is 220 instead of the 110v used in the US, say a domestic market Kamjove. The upside to this is that domestic Chinese kettles are very cheap (but understandibly hard to find in the US). I was given mine by the owners of a Fujian tea company, but some Chinese tea shops will special order them for you.

This kettle won't work in your standard US outlet, nor will the plug fit, but if you order a portable step-up/step-down power transformer you can convert your 110v outlet into 220v. Amazon sells a variety of these. You'll want one that well exceeds the wattage of your kettle, which unfortunately means you need one of the more expensive models like the $88 2000w version I linked to. Smaller wattage transformers are much cheaper but will blow a fuse at the demands of a kettle. A plus of this model is that it has a built-in plug adapter for a variety of international standards.

Like I said, I have a domestic Chinese Kamjove and this transformer and love it. I have boiling water in well under two minutes, and it's a durable set-up (been using it many times a day for over two years)

They will not work with an 110v American plug. I just use a step up converter like this.

http://www.amazon.com/Bright-VC2000W-Voltage-Transformer-converter/dp/B000MXW85A/ref=sr_1_1?s=lawn-garden&ie=UTF8&qid=1451873233&sr=1-1&keywords=2000watt+step+up