(Not reading-related)
Shazam - it's an app (free) for those times when you hear some music in a store or on the telly but don't know what it is. You run Shazam, it "listens" to the music, and then analyzes it and (most times) comes back with the track name (and, of course, the option to click through to iTunes to buy it
).
Weather - get OzWeather or PktWeather ($2.49). At the mo' I prefer the former. They cost, but they're worth it, because the built-in weather app is crap, its forecasts never seeming to be accurate or have anything to do with what the BoM is showing. Plus, the bought apps show extra stuff.
The ABC app's (free) not bad either, if you're an ABC watcher/listener/reader.
NSW Food Watch (free) - This app works off the NSW Food Authority database to highlight (by "Nearby", "Map", or "Latest") those food places (restaurants, bakeries, etc.) that have been naughty in regards to hygiene, etc. It's an excellent app, though might make you a bit paranoid.
They're just some I use on my iPod Touch (I might be getting an iPhone 3GS shortly).
Cheers,
Marc