They call it "GovHack" but don't be alarmed: these self-proclaimed geeks are here to help.

More than 1300 programmers, designers, students and other inquisitive folk took part in this year's weekend-long "hackathon" across Australia, which finished on Sunday night.

Canberra Grammar School students James Treloar and Sam Moore conspire at GovHack. Credit:Rohan Thomson

The fast-growing event has a simple premise: over 48 hours, build something clever with government data and have fun doing it.

This year's sponsors, including government agencies, will stump up prizes worth $70,000 for the most creative and useful "hacks", or applications, crafted from public data.