Photo Mosaics are actually a very new invention, believed to be first created in the 1990's. Photo mosaics have become widely popular around the world, though, for their unique appeal.
A Photo Mosaic is a photo made up of many smaller photos. To say it another way: A photo mosaic is a photo that has been divided up into small squares or rectangles. Each rectangle is the replaced by a separate photo that closely approximates the color the rectangle was.
A picture is worth a thousand words in explaining what a photo mosaic is like, though. Go to Google Image Search or Yahoo Image Search and search for “photomosaics”.
One of the first creators of photo mosaics, Robert Silvers, patented the production of and name photomosaic. However, Mr Silvers patent does not give him the exclusive rights to make photo mosaics. There are many companies around the world using various methods and technologies to legally create photo mosaics.
There are several ways to create or obtain photo mosaics.
The first method is tedious, to say the least. Using photoshop, or any other editor, you can manually cut and paste images together to create the larger image. This technique is very time consuming, though, and there is really no need to employ this method.
The second method is to use photographic mosaic software. There are many versions of free software that can help you much more easily create photo mosaics. Of course, there will be at least a short learning curve, but most are not too difficult to use.
The third and final method to obtain a custom photo mosaic is to pay a professional photo mosaic designer to create on for you. This is obviously the most expensive option, but it will probably also give you the highest quality finished product.
Really, it's all up to and what you need and want! Happy photo mosaic-ing!