Is it ok or safe to use a digital camera onboard?

Or an ipod and stuff that have batteries in them

Yes. It is ok.

But during take off and landing, you will be asked to turn electronics equipments off - especially mobile phone. Just read and listen to instructions and you will be fine.

I have taken photos of friends when we boarded the plane and have used music players. No Problems.

yes but you must turn it off during the take off and landing of the plane

digital cameras yes ipods yes