Bed Bath & Beyond
They sell some great micro fiber cloths in a 10 pack and I use those for my iPhone cleaning. I wet one with water, ring it out really well, then I wipe the whole phone down thoroughly and use the dry one for the drying. Take in mind that the cloth is just damp, not wringing wet. The dry cloth is used for the final polish. I clean my phone every other day. I have ghost armor on front and back & on the side. My iPhone 4 was/is still in mint condition because I always use these cloths to clean it with. I'll continue to do this with my 4s. Works great.