M_Boats: solar panels..

I have a 5W solar panel that I got for purposes of trickle charging my 12V house battery. It only provides a few hundred miliamps of power. There are solar panels specifically dedicated to recharge AA, AAA, D, and C batteries but I'm wondering if I can somehow use the solar panel that I already have. Is there a 'black box' I can run the solar panel through to recharge such things as cell phones, rechargeable AA battery packs, etc? Any advice would be great!! Joe