>I will often put several non-visual classes in one class library (one file) and for visual classes it's usually one class per file. A notable exception being my class library that sub-classes all the UI controls ... you know, TextBox, ComboBox, etc. Though these are visual objects, they can't be sub-classed visually and since there's potentially not much code in some of those sub-classes, I don't find it a very good idea to have a file for each class.

Another "it depends" :)

For me, I have two classes that contains over 2000 lines of code. So, having them in separate files with the name of file as the class name, for naming convention, it was also a good decision for me. Now, as to know about those who think that a class should be really small in terms of coding, well, they are entitled to their opinions. For me, the list and the data entry classes are two big huge classes that need to be defined as is for my own standardization. And, I like that as is. :)