I tried to do a search to see if this was already on the board. I couldn't find it so I will post just in case. (this may be old news that I just figured out)
First you have to google a free list of proxy's. Then go to firefox.
when on firefox go on tools.
click on options.
then Advanced
click on network
under connection (configure how firefox connects to the internet)
click settings.
Then put the dot on Manual proxy configurations
Put one of the free proxy's from googles in don't forget the port #
Then check the box right under use this proxy server for all protocols.
Now you have a free proxy.
You can change #s whenever you want. or change back ip by direct internet connection.
Like I said, I am sorry if this is old news. I just figured it is easier then unplugging everytime. Plus when I unplug I only change ip's by one number.
The complete step-by-step guide to get back to selling today!
Proxies are not really recommended for ebay, they arouse suspicion. Its much better to think of other ways of how you change you're WAN IP either through the router or through your cable modem, or alternatively through dialup.
doooont use those. ebay can find out that you are using proxies. also these free proxies are not reliable, and you might have to get a new one everyday - this crazy ip address changing everyday will put up some red flags on ebay. also, anything you send through these proxies (including your usernames, passwords and any other "sensitive" info) can be recorded by the proxy owner.
so i dont suggest using proxies for ANYTHING.
This is how I changed my own Ip address. 
