I was at a concert yesterday and wanted to take a picture without a flash so I set the applet for "no flash" and then set the Scene Mode to "nighttime".

When I went to take the picture, the N97's camera during the focusing turned on the LEDs briefly. The didn't flash, but I would have expected the LEDs to not have lit up at all.

The LED lights up to help the lens focus, happens on normal point and shoots as well

Yeh I noticed this aswell, I was trying to take a sneaky pic of the missus but the LEDs came on.

Is there any way of turning of the LEDs?

i don't know, i don't own the phone anymore however i would look through the settings