A:Answer it depends on what kind of cellphone you are using. if you are using an iPhone or Nokia or any phone that has a 3.5mm round minijack for your earphones, you can use these speakers on them.
I've attached a picture of iPhone showing the 3.5mm jack.
if you are using a Motorola phone that has sort of a flat connection for the earphones, you won't be able to plug these speakers in.
these speakers are only just speaker units, you can't insert CD's in them anywhere.
FYI, these are real good speakers, bass is perfect (at least to me it is), clear sound, and can get really loud for partying. I have them for three years now, still good as new, and I'm still loving them!