Splitting CamelCase

I used:

    public static string SplitCamelCase(string input)
    {
        return System.Text.RegularExpressions.Regex.Replace(input, "([A-Z])", " $1", System.Text.RegularExpressions.RegexOptions.Compiled).Trim();
    }

Taken from http://weblogs.asp.net/jgalloway/archive/2005/09/27/426087.aspx

vb.net:

Public Shared Function SplitCamelCase(ByVal input As String) As String
    Return System.Text.RegularExpressions.Regex.Replace(input, "([A-Z])", " $1", System.Text.RegularExpressions.RegexOptions.Compiled).Trim()
End Function

Indeed a regex/replace is the way to go as described in the other answer, however this might also be of use to you if you wanted to go a different direction

    using System.ComponentModel;
    using System.Reflection;

...

    public static string GetDescription(System.Enum value)
    {
        FieldInfo fi = value.GetType().GetField(value.ToString());
        DescriptionAttribute[] attributes = (DescriptionAttribute[])fi.GetCustomAttributes(typeof(DescriptionAttribute), false);
        if (attributes.Length > 0)
            return attributes[0].Description;
        else
            return value.ToString();
    }

this will allow you define your Enums as

public enum ControlSelectionType 
{
    [Description("Not Applicable")]
    NotApplicable = 1,
    [Description("Single Select Radio Buttons")]
    SingleSelectRadioButtons = 2,
    [Description("Completely Different Display Text")]
    SingleSelectDropDownList = 3,
}

Taken from

http://www.codeguru.com/forum/archive/index.php/t-412868.html