Running a server without your ISP knowing..

Ok....say I knew someone who wanted to ru a server....but his ISP wouldnt let him.
But he though "Well I pay for bandwidth anyway so Ill do whatever the %$*& I want".
So he has the server software setup and a free trial thingy from www.dynip.com and is trying ot figuer out way to hide the fact hes running a server fro his ISP.

heres the suggestion our friend has gotten so far..
Run a hardware and a software firewall.
Connect through a proxy so it looks like your only uploading to 1 ip.

Ok, so whats a good free proxy to connect through and what else can he do..

he thanks you for your help...of course..