Binary comparison of files

Hello again,
 
I need to quickly check if the content of a file has changed. Time stamps
when the file is created are not available, as this file is read from the
Internet with XmlTextReader. I was thinking to use a quick binary comparison
of the old image (provided I keep one) with the newly red file. Files are in
size between 100 kb and 150 kb, so not too big. I need to come up with the
fastest way to compare the files, because timing is an issue.
Any suggestion as to what may be the best approach to do this?
 
Regards,
Eddie

===================================
View archives and manage your subscription(s) at http://peach.ease.lsoft.com/archives