This VS2008 or higher extension uses a LINQ statement to remove duplicate items from a string array but is not case sensitive, also you might like to leave the sort/order-by in the extension or remove it.
Example
Dim Names() As String = {"Bob", "Mary", "bob", "Bob", "Jane", "Kevin", "Jane"}
Names = Names.RemoveDuplicates
For Each Name As String In Names
Console.WriteLine(Name)
Next
Returns
bob
Bob
Jane
Kevin
Mary
Extension (place in code module)
<System.Diagnostics.DebuggerStepThrough()> _
<System.Runtime.CompilerServices.Extension()> _
Public Function RemoveDuplicates(ByVal sender As String()) As String()
Return (From value In sender Select value Distinct Order By value).ToArray
End Function