Batch photo editing - Watermark and resize

Sabre Systems have a new ecommerce website and wanted to add their numerous photos of boiler spares, tools, consumables etc. All there photos where in different folders, different sizes, and needed to have a thumbnail size and fullsize photo created which were all watermarked.

How long would it take to do this lot by hand?! A Perl script was written incorporating ImageMagick and ActivePerl which allowed for all to be done at once - and reused on future photo batches.