Headphone connection question/help

I recently bought a new power PC and one thing I forgot to look for was that it has a front audio jack for headphones.  Of course now that I have the PC, it does not.  So my question is, does anyone know if they make an adaptor for the headphones to plug into the USB or do they make headphones that plug directly into the USB port.  I use headphones alot as to not to disturb others in the room (IE wife) and this lacking feature is not good.  I need a way to connect headphones  (and not headsets you can talk into, I have these) to the USB, either by an adaptor if one exsists or USB headphones  (if these exsist).  If anyone is using anything out there and it is good, please let me know...

Thanks

I recently bought a new power PC and one thing I forgot to look for was that it has a front audio jack for headphones. Of course now that I have the PC, it does not. So my question is, does anyone know if they make an adaptor for the headphones to plug into the USB or do they make headphones that plug directly into the USB port. I use headphones alot as to not to disturb others in the room (IE wife) and this lacking feature is not good. I need a way to connect headphones (and not headsets you can talk into, I have these) to the USB, either by an adaptor if one exsists or USB headphones (if these exsist). If anyone is using anything out there and it is good, please let me know...

Thanks

Vortimous