StarHub in Singapore have stores that offer a 3G standard-sized SIM for SGD$18 (you have to show your passport when purchasing the SIM so your personal details can be kept and associated with the number). Once bought a data plan can be purchased as detailed here. I chose the 1GB valid for 7 days plan at $7 by dialing the number *131# and following the prompts.
The performance of the Internet was terrible. Just abysmal. During peak times there’d be absolutely no data flow whatsoever (not even the most basic HTML pages could be loaded). Other times (say, 4am or 10am on occasion) the connection was fine! Not really worth relying on but as some hotels (Amara Hotel is one such offender) charge $30 per day even the limitations on the StarHub offering is economic for some tourists. Of course some other hotels offer free Internet (Changi Village Hotel is such an example).
The remaining balance on my account (which should have been SGD$18 – $7 = $11) seemed to completely dissapate by the time I returned to Singapore a month later for some reason. Bizarre.
2 degrees mobile offer a Mobile Broadband Data plan of 1GB for NZD$20 valid for 1 month (but “autorenews” unless you SMS “STOP MBB” to 233 immediately after activating the data plan by texting “buy 1gb” to 233).
You can go into a store, buy the SIM for NZ$10, and get a top-up voucher for $30. You then register the SIM by calling 200 which just involves setting a PIN number on the account. No passport information is needed.
Then you top up sending the code from the top-up voucher you purchased when buying the SIM.
The Internet seems not too bad.
I bought a Virgin Mobile SIM from a corner store in the centre of Sydney for AUD$2. I also bought a top-up for AUD$29 which I applied AFTER I called the registration number and spent 20 minutes on the phone with somebody in India or China telling them where I lived etc (note you have to explicitly request to be put on the $29 cap plan before you apply your top up voucher).
The caps were listed at this web page at the time of this blog post. By the time you click on the link it may have disappeared. But in February 2013 it offered for the AUD$29 1GB of mobile data to use within 30 days.
You can check your balance by logging into the “My Account” webpage with your phone number and a 6-digit PIN you allocate during that registration phone call you did when setting up the SIM card – but the “My Account” will not tell you how much data is remaining (and that is below the standard I would expect of a reasonably competent mobile operator).
Performance seemed okay for my purposes. Australia is changing. Two or more years ago you would have been forced to pay outrageous amounts ($30 for a day or $10 for an hour) for Internet in a hotel or airport. Now both Melbourne and Sydney airports offer free Internet (usually capped around 500MB) and some hotels (Meriton Serviced Apartments in Sydney, for example) are now offering free capped Internet, too (usually capped around 1GB per day per room).