I'm trying to think of the name of a group whose music I quite like.

They have only come to prominence in the last year or so and were featured on one of the evening shows on Radio 1 (Zane Lowe, I think). They had a single or two out.
Fronted by a female vocalist. From New Zealand I believe and sound a little bit like Evanescence

Any ideas, anyone?

The Naked and Famous? http://www.youtube.com/watch?v=gqUJdcCjUIA

No, not them.

Ladyhawke?

It was Tonight Alive.

They're not from New Zealand though - they're Aussies