you ISP address will be something like :
TalkTalk Correspondence Dept.
PO Box 360,
Southampton
SO30 2LY
Think you might mean your IP address, which is your computers unique address on the internet.
It is not possible to hide totally, there are services that offer anonymous browsing by basically directing all traffic through their computers so it looks like you are located where ever their computer is. But, these services keep records so you could still ultimately be traced back.
to be honest, I can see very little benefit for most people wanting to be anonymous on the internet unless they are up to something underhand, in which case I have no interest in helping.