There's plenty of good free iPhone apps, but for some functions, you're going to end up shelling out some cash. How can you be sure you're not paying too much for an application that occasionally goes on special?
At PC Authority, Alex Kidman covers two applications, PandoraBox and AppSniper, which track the pricing of applications you're keen on and send alerts if the prices drop. PandoraBox has one big advantage over AppSniper: it's free. You won't always get savings -- as the article points out, the pricing is in US dollars, and some discounts don't translate into Australian prices as well -- but it's a no-cost way of minimising overspending on nice-but-not-essential apps.