My ISP is threatening to disconnect me for using Limewire file sharing. What can I do? I am not sharing porn of any kind just music and some programs that I have downloaded.

a) change ISP
b) porn is not illegal in most places in the world

First of all, using LimeWire isn't illegal and the ISP has no right to disconnect you for using LimeWire if it this isn't a direct violation of his terms of use.

So if you aren't exceeding your bandwidth limit, and your ISP didn't tell you which files exactly he doesn't want you to share, ignore it.

If the ISP told you which files violated any other parties copyrights, - stop sharing those specific files.

its obvious that they don't allow servers on their system.
put up a firewall so they can't port scan you, or get a new ISP.
people will still be able to get your files through push, and your port 6346 won't be open so they may not be able to tell you are running gnutella.
switch to a program that allows you to throttle up/down speed so they won't get so mad at your use of bandwidth, lay low for a while then crank it back up within reason. Gnucleus will let you do this.
pay them for server privledges

Your ISP can see every file you send / receive and it can easily find any gnutella traffic no matter on which port it is sent, so I doubt this will help.

Which ISP? Just curious

Well, it’s official. Unless I turn off my share capability I’m booted. One more offence and I’m back to 24,000 max connection. Out here in this Michigan countryside there isn’t a lot of options. Cable that is to say,” Charter Communications” just became available within the last six months. They say that according to some new law, they can be held liable if they allow me to distribute what they term "illegal software". The operative word is distribute. I asked to face my accuser so I would know who’s toes I stepped on. They said they could not disclose this information that if I were a hacker I might retaliate. Yeah right, if that were the case I wouldn’t have been zapped. I never even installed the software, (on this system). So the leak isn’t there. The software consisted of stuff like Adaptec easy cd, Adobe stuff, Microsoft programs and MCSE stuff, Macromedia, Bryce and the like. Pretty much anything that was a program I snagged, just to check out. You know, if I liked it, I would go out and buy it. There is obviously some spyware in there somewhere feeding info to BIG BROTHER. I’m firewalled to the MAX. According to LeakTest my computer is invisible to the net. Any way I’m telling you this so you will beware. PS. I never killed an upload, and I always enabled ultrapeer while I could. I’m open to suggestions. ROCK ON!!!

You can never be invisible to your ISP, although it's probably been MediaDefender or some other company searching gnutella for copyrighted material.

I don't think your ISP can order you to turn off sharing, since sharing files (if you are not infringing anybody's copyright) is completely legal.

Just stop sharing those programs, for it is very likely that in the name of Adobe or Microsoft a company like MediaDefender sent a letter to your ISP telling him that you are sharing copyrighted material.