Photoshop CS3 will allow you to split the photos into layers and alter the look of them to make the layers, which can be the clothes, different shades of yellow, brown, and grey, which will make them look like old photographs. To actually change the clothes in the photos to old fashion clothing, you'll need to find photos where people are in similar, preferably same, poses and cut and paste. Then smooth the transition edges between the figures in your photos and the old clothing layered on top so that it looks as if they're actually wearing the clothes. To make the altered photos believable will take time and finesse.