Hints: Visual Studio (version 2005)
Line Length Guidelines
It is commonly accepted that code should contain no more than 80 characters per line, and many editors therefore draw a vertical guideline at 80 characters (if a different line length is desired, you can often choose the cutoff point). Visual Studio 2005 doesn't appear to have this feature, but in fact it is hidden away for reasons I know not.
To turn the guidelines on, open the registry editor (Start Menu > Run... > regedit.exe) and go to
HKEY_CURRENT_USER\Software\Microsoft\VisualStudio\8.0\Text Editor
In here create a new String Value with the value 'RGB(100,100,100), 80'. The RGB value determines the colour of the guideline (grey in this example) and the second value determines where the line appears (after 80 characters). You can add extra guidelines with additional values (e.g. 'RGB(100,100,100), 80, 100' for lines at 80 and 100 characters).