Case insensitive List

No you cant create a case insensitive list. However you can do a case insensitive Find in a list, heres how :

List myList = new List();
string colorToTest = "RED";
myList.AddRange(new string[] { "red", "blue", "green" });

bool colorPresent = myList.Contains(colorToTest); // returns false

colorPresent = myList.Exists(delegate(string str){
return str.Equals(colorToTest, StringComparison.OrdinalIgnoreCase);
}); // returns true

Maybe using extension methods i can provide a case insensitive Find to a List.

BTW, you can get a case insensitive Hashtable by passing StringComparer.Ordinal in its ctor.