Make your photos huge!
Just saw this great site, the Rasterbator – all you do is upload a small photograph (less than 1MB), then the site generates a pixellated version of it which you can then expand and crop to fit on many, many sheets of A4 paper. We did a massive one of our boss who’s away today and stuck it on the wall. It fits 6 A4 sheets across and 7 A4 down!