Whilst it was all well and good Apple throwing in a camera zoom feature in iOS 4, it doesn't get away from the fact that a digital zoom is always a bit, well, rubbish.
What you need is a proper lens with optical zooming on your iPhone - if you want to take decent long distance snaps that is.
One like the one you'll find packed into the Eye Scope for iPhone 4.
Basically the Eye Scope is a case for your iPhone that has a adaptor on board for screwing on the 8x magnifying lens.
In the box you'll get a mini tripod and a bracket for attaching your phone if you want to do some more professional shooting sessions, but you'll also just be able to slip the lens in your pocket, keep the case on your phone and screw it on when you're out and about and you see something far off that needs snapping.
Whilst your iPhone 4 is never going to be a direct replacement for a mid or high-range DSLR camera, the Eye Scope does add a bit of functionality that you wouldn't normally have access too. And, as you can see from the before and after shots below, the results are pretty effective.
There's a manual dial on board, so you can get the exact focus that you need and the magnified image appears right on your iPhone's display. It has a minimum focus distance of 3m and will offer a field view of 246m.
It's a fun little accessory and could be just the job for a bit of papping on the fly.
The Eye Scope for iPhone 4 is out now, and will cost you around £29.99.