Came across this great article that shows some useful things that you can use when writing a custom configuration classes.
Things i found useful:
  • Has good examples
  • Lists all validators that are available in .NET 2.0 (e.g. RegexStringValidator)
  • Lists type converters (e.g. CommaDelimitedStringCollectionConverter)
  • Performance optimisation tips
Custom configuration proved to be every useful indeed. Writing custom configuration classes might look a bit over the top at first, but it's actually very quick and easy.

Another useful resource is here