I totally understand. Here is your code, tweaked a bit:
PHP Code:
<?php if( is_category( 'Thinking It' ) || in_category( 'Thinking It' ) ) { ?>
thinking it #1 <a href="http://s1132.photobucket.com/albums/m576/iandarley/Snapbucket/web%20graphics/?action=view&current=ThinkItOffer.png" target="_blank"><img src="http://i1132.photobucket.com/albums/m576/iandarley/Snapbucket/web%20graphics/ThinkItOffer.png" border="0" alt="Photobucket"></a>
<?php } elseif( is_category( 'Doing It' ) || in_category( 'Doing It' ) ) { ?>
doing it #2 <a href="http://s1132.photobucket.com/albums/m576/iandarley/Snapbucket/web%20graphics/?action=view&current=DoingItOffer.png" target="_blank"><img src="http://i1132.photobucket.com/albums/m576/iandarley/Snapbucket/web%20graphics/DoingItOffer.png" border="0" alt="Photobucket"></a>
<?php } elseif( is_category( 'Living It' ) || in_category( 'Living It' ) ) { ?>
living it #3 <a href="http://s1132.photobucket.com/albums/m576/iandarley/Snapbucket/web%20graphics/?action=view&current=LivingItOffer.png" target="_blank"><img src="http://i1132.photobucket.com/albums/m576/iandarley/Snapbucket/web%20graphics/LivingItOffer.png" border="0" alt="Photobucket"></a>
<?php } ?>
Note that I changed the "Category #1", "Category #2" and "Category #3" bits to your actual Category names.
Eric