SharePoint allows you to create custom web parts to help you provide highly customized solutions to your clients/users. The properties of these web parts are added by default but to further customize the solution, you can also create custom properties. The following example demonstrates how to add a custom dropdown property to a custom webpart.
// Create a Enum for Languages
public enum LanguageByEnum
{
English = 0,
French,
Spanish
};
Thanks,
Eliza
http://www.mindfiresolutions.com/Sharepoint-Support.htm