Data allowances on mobile phones are more generous than ever, but the costs are still high compared to home broadband. We run down the basic tactics you can use to ensure that you don't suffer from a nasty case of bill shock.

The good news? Telstra's Whereis site has released an Android-specific GPS app which supports voice recognition, offers turn-by-turn navigation and even includes built-in flight timetables and pedestrian mode walking directions. The bad news? It only works on phones connected to the Telstra network, and you have to pay $15 a month for the privilege.

Smart phones are becoming an increasingly common choice even for casual users, but the whole area can seem confusing and overwhelming for new buyers. Lifehacker 101 guides you through the main platforms available.