I have stopped using the term Photomosaic, which with this spelling has been registered as a trademarked by Robert Silver. I use the professional version of Andrej Olenik's Mosaic Creator, which is based on different patented techniques to those covered by the patents filed by Robert Silver through Runaway Technology Inc.
There is a good article on the photographic mosaic process in general on wikipedia, including discussion of the trademark issue. Also worth following up are Joseph Francis's History of Photo Mosaics and WL Hunt's History of Photo Tiled Pictures.
From now on I will be referring to my photographically tiled works as photo impressions, and the multi-image panoramics and other similarly multi-image constructions as just multi-image and/or collages