So it turns out Brits travelling to Australia get more competitive data rates roaming than we get living here.
Although you risk having your account terminated for unusual use, it's pretty tempting (though I haven't tested it yet). It used to be even better (where all-you-can-eat data plans gave you up to 25 GB) but now you are limited to 12 GB a month for an all-you-can-eat plan, which is still cheaper than anything here. You could get a pre-paid monthly top-up for 20 GBP (~$41.52 AUD), while those on month-by-month plans can get as low as 17 GBP for 12 GB. The best part is you'd get unlimited data if you ever visited the UK and you can use this feel-at-home feature in several European countries, US, NZ and more (Australia, Austria, Denmark, Finland, France, Hong Kong, Indonesia, Israel, Italy, Lanzarote - Spain, Macau, New Zealand, Norway, Republic of Ireland, Spain, Sri Lanka, Sweden, Switzerland, United States). Read about it here: http://www.three.co.uk/Discover/Phones/Feel_At_Home
Unfortunately the rules are strict and getting stricter. For example, now you can't go more than 2 complete months in a 12 month period in one destination without being blocked (and they might screw you over prematurely if they're suspicious). You also can't tether or use p2p software (but VPNs are OK but slow).
Has anyone been secretly exploiting this or similar deals (if any exist) from other countries?
Update: I think when roaming the data may be restricted to 3g.
looks good, partners include Telstra. Optus . Might have a pommie relative coming to stay with me soon, for two months!