Programs for gel image analysis?

[Tom Duda]

I have been contemplating the use of image analyzing equipment for
analysis of gels.  I am currently using an image analyzer and some fairly
simple programs to measure the shell lengths of clams (1000's a day -
maybe?).  I have run numerous gels for my thesis and was curious about the
use of image analysis in analyzing gels.  Is this a common practice?  What
software is commonly used?  It doesn't seem that a sophisticated yet
simple program would be too difficult to write.

E-mail me directly or post here if you have any info.  Thanks!