Terminal screens can use backgrounds in OS X Lion. To configure these settings, open Terminal and choose Preferences from the Terminal menu. Then click on the Window tab. Use the Image drop down to select Choose. This brings up a browse dialog box that you can use to choose an image. Browse to the image and then click on Open. Choose images that are pretty much all dark or all light as your font should be the opposite color.

Save time.  Don’t touch a lot of photos one at a time.  You can resize images en masse using a variety of tools on the Mac or Windows.  Most notably, Photoshop.  But there are also less expensive tools, if not free ones out there.  For example, RightThumb.  RightThumb lets you resize images, filter images, change formats, add prefixes, etc. Nice little tool and free to boot.