Wouldn't it be great if you could take a picture and determine the area of a leaf or the distance between two objects?  Wouldn't it be great if you could do that over a series of images?  How about quantifying changes in color over time? These are the kinds of questions that an image analysis program can handle.  Some programs are expensive, and some are even free.  One of the very best free programs is Image J.  It will do all the above and more.  Labs across the country have created plugins that do specific analytical tasks, such as gel analysis.  The good news is that the price is right, and the software is powerful.  The downside is a definite lack of user friendly manual. If you have used Image J, please chime in!