>If you're worried about speed, shouldn't you drop the linq statement to list, and use the list in the foreach control. That way the linq is not executed for each iteration of the foreach.

Not really worried about speed but if you mean something like this:

List<TextBox> l = Controls.OfType<TextBox>().ToList();
            foreach (TextBox c in l)
            {
                c.CharacterCasing = CharacterCasing.Upper;
            }

then No, I don't see the point. It's creating a List of TextBoxes needlessly - better just to use the IEnumerable returned by 'OfType'



>>>A better LINQ way:
>>>

foreach (TextBox c in parentForm.Controls.OfType< TextBox>())
>>>            {
>>>                c.CharacterCasing = CharacterCasing.Upper;
>>>            }

Good. I'd forgotten about OfType(). Don't know if it's any faster because, internally, I think it does a 'is X' anyway ?