I agree with Pat.
your original question was "what is spoofing ?"
in most instances, spoofing is an attempt by someone to steal from you. they fake their information in order to make you think they are someone else.
that is likely what resulted in that IP address you use getting banned to begin with.
here is one type of spoof :
http://www.getmysiteonline.com/FightingSpam/Spoofs.asp
if there is a problem with that IP address, then contact the people at the Cafe and request user logs and information about the ban, and the action they took to prevent it from happening again (like banning that person from ever stepping foot in the cafe again), then submit that to the website you have been banned from.
on a separate note :
if you do spoof your information for your legitimate business, and your legitimate customers realize it, they will think you are a scam artist and that WILL get you banned from a lot of sites, including getting your email addresses terminated by your providers.
Its bad to be banned, but if your email address is terminated, it can cost you months of work to reset other accounts associated with or registered with that email address.
Overall.. bad idea.