This really depends on the type of image you want to display. If it is one large image, I would suggest a medium quality jpg, that will preserve the color depth, and still keep some image quality. However, if you want transparency, then there are a few things you can do. First disable anti-aliasing on the selection tool you are using. Then set the background color to an alpha channel color. The best/most commonly used color for a transparency is an RGB value of 255,0,255. This is an ugly bright pink color. Set this as the background color. Then make a selection of the area that you want to be transparent, and hit delete. Using this method will prevent your image outline from having a "fuzzy" edge when you export it to a .gif file. One thing to remember is that once you get your un-antialiased edge, if you copy the image and paste it in another layer or image, Photoshop AUTOMATICALLY will antialias it again, so you will get a fuzzy pixel pink edge on your image. Then when you are exporting the image, be sure and specify the same RBG color value for the transparent color. co(V)(V)union