How do I make a solar charger for 8 NiMH batteries?

I want to use solar power to charge batteries to use to charge electronic devices (phone, ipod,etc.), and put it in a backpack.  Is there any way to modify a regular AC NiMH charger to safely charge the batteries?  Or do I have to make my own?  Also what do I have to do to regulate the final power coming form the batteries to charge the device safely.  I know that there are instructables on this, but some contradict the others and most don't include all of the things that I need in one instructable.

Thanks in advance