Information as of March 2012.

I am in Cambodia now (only Phnom Penh), so let me update the info on the Hello SIM. It is called the Hello Travel SIM Pack and it is bought at the stall described above when exiting the airport, the girl will give you the SIM and an instruction sheet for checking balance, finding your number, changing your language, etc. To activate, put the SIM in the phone and try and make a call.

Price is $5, which includes $3 in regular credit and $7 in "onnet credit". I *think* this onnet credit is only for calls to other Hello users, as mine has stayed at $7. SIM expires after 10 days of inactivity, which is not a problem, just buy another one on your next visit.

I received calls on the SIM from Cambodia and USA, and quality is good. Calls to the USA are 13 cents/min, from what I remember.

The best thing about this SIM is that I am getting 4G coverage within Phnom Penh. Just did a speed test, it is 3.10 Mbps up and 1.72 Mbps down. Really great!!! My phone is a HTC T-Mobile MyTouch 4G. Cost of Internet is:1 cent per 500KB, so 50MB for $1. Cheap. If you want a larger package for internet, you can get a 400MB bundle for $2 by typing *8880*7# ... incredible value, IMHO.

APN is: hellowww

You can add credit all over the city at the stalls on the corners, just ask around. Credit comes in as little increments as $1.

Color me impressed by the cost, coverage and speed. Last time I was here, mobile calls and Internet were spotty at best

Tons more info here, including instructions, rates, Internet packages for larger volumes, etc.: http://www.hello.com.kh/public/international_services/international_services.aspx?page=is_hello_travel_s im_pack

FYI, a friend here has the Beeline SIM, it is cheaper ($2) and reliable and calls to USA are 8 cents (I think). No 3G or 4G coverage though, so Beeline is only an option if you don't care about Internet.

Off to Indonesia next.