Trust me this really works, I didn't believe it till I tried it, but the results just blew me away! take a normal image, even a scanned 6"x4". Under Image menu chose Image size, make sure resample image is selected, change the unit of measurement from inches to percent and type in 110 to increase your image by 10%, and this is the cool bit, by increasing your image in 10% increments, for some bizarre reason it doesn't seem to soften or blur the image. Obviously to get the image up to poster size it will take quite a number of iterations of the increase by 10%, but if you have Photoshop 7 or above, (or elements I think) then you can create a custom action to do it for you at the press of one key! I have used this to print a 6x4 scan at A2 size, the results are astounding, equally as good as using an expensive plugin such as genuine fractals, and for no extra cost!!