Generally: yes, you can point an unlimited number of domains at the same web site.
Whether or not this is possible will largely depend on your web host's setup, and what they allow their clients to do.
A concern you may also have in so doing, is the "duplicate content penalty", wherein two websites would look, to search engines, to possess identical content, and therefore one of the sites would be penalized for the duplication… Since you could not necessarily CHOOSE which domain would carry the penalty, it's worth thinking things through thoroughly before pursuing this course.
Alternately, you may set one domain to point at a certain part of your site (a particular subcategory, for example), and then prevent search engines coming to the second domain from searching that subcategory.
deano.com 