Prepaid is no longer the poor man's postpaid when it comes to mobile data -- how'd you like 4.8GB on your next recharge?

Who says you need to go on a long-term contract to get enough data to use on a smartphone? While prepaid mobile has traditionally been lacking in any worthwhile data options, both Telstra and Virgin Mobile have some seriously good deals going at the moment that will satisfy even the most voracious of power users.
Telstra offers a lot of variety with its prepaid plans, letting you mix and match different offers and bonuses to use up your recharge amount. A $40 recharge with Telstra's Pre-paid Cap+ offer gets you $260 of credit, 150MB of data, and $40 that you can spend on any of its Plus Packs. In this case, we'll use it on a $39 Browse Plus pack, which gets you an additional 750MB of data. Altogether, that's 900MB of data for $40.
If you move up to a $60 recharge, you get $440 of credit and 300MB of data, plus $60 of credit that you can spend on a $49 Browsing Pack (which comes with 2GB of data) and a $10 Browsing Pack (for 150MB of data). Add it all up and that's 2.45GB of data altogether, which is significantly more than what you can get with any postpaid plan in the same price range.
Not satisfied? A $100 recharge will get you 4.8GB of data and $900 of credit. You may be able to
get a better deal on a Telstra postpaid plan by swapping out the data component for a higher-value browsing pack, but otherwise this compares very favourably with the $99 postpaid plan from Optus, while Vodafone and 3's $99 postpaid plans only come with 3GB of data, and Telstra's standard $99 cap only comes with 1.5GB of data.
But the prize for cheapest prepaid data goes to Virgin Mobile. Every recharge, starting at $19, comes with a bonus 1GB of data. You can accumulate up to 5GB of data at a time simply by recharging before the 30-day expiry period, so recharging the $19 cap twice for $38 gets you 2.1GB, three times for $57 gets you 3.15GB, and so on.
The catch (you knew there had to be one) is that the offer is only valid until 31 August 2010. But even if Virgin Mobile withdraws the offer at that date (in our experience, however, these sorts of deals seem to hang around indefinitely), you'll have almost a full month to use all the data if you pick up a prepaid pack today. Virgin Mobile also includes unlimited calls and text to other Virgin Mobile users and free voicemail, and this is a standard feature that doesn't expire.