ArrayLists, Generic Lists, Is There A Way To Insert Items Faster?

Public Class LinkedArrayEnumerator
    Implements IEnumerator

    ' Fields
    Private mCurrentElement As Object
    Private mCurrentList As ArrayList
    Private Shared mDummyObject As Object = New Object
    Private mIndex1 As Integer
    Private mIndex2 As Integer
    Private mList As LinkedArray
    Private mVersion As Integer

    ' Methods
    Friend Sub New(ByVal list As LinkedArray)
        mList = list
        mIndex1 = -1
        mIndex2 = -1
        mVersion = list.mVersion
        mCurrentList = Nothing
        mCurrentElement = LinkedArrayEnumerator.mDummyObject
    End Sub

    Public Function MoveNext() As Boolean Implements System.Collections.IEnumerator.MoveNext
        If (mVersion <> mList.mVersion) Then
            Throw New InvalidOperationException("InvalidOperation_EnumFailedVersion")
        End If
        If mCurrentList Is Nothing OrElse mIndex2 >= mCurrentList.Count Then
            If mIndex1 < mList.mLists.Count - 1 Then
                mIndex1 += 1
                mCurrentList = mList.mLists(mIndex1)
                mIndex2 = -1
            End If
        End If
        mIndex2 += 1
        If mCurrentList Is Nothing OrElse mIndex2 >= mCurrentList.Count Then
            mCurrentElement = LinkedArrayEnumerator.mDummyObject
            mIndex1 = Int32.MaxValue
            mIndex2 = Int32.MaxValue
            Return False
        Else
            mCurrentElement = mCurrentList(mIndex2)
            Return True
        End If
    End Function

    Public Sub Reset() Implements System.Collections.IEnumerator.Reset
        If (mVersion <> mList.mVersion) Then
            Throw New InvalidOperationException("InvalidOperation_EnumFailedVersion")
        End If
        mCurrentElement = LinkedArrayEnumerator.mDummyObject
        mIndex1 = -1
    End Sub


    ' Properties
    Public ReadOnly Property Current() As Object Implements System.Collections.IEnumerator.Current
        Get
            Dim currentElement As Object = mCurrentElement
            If (Not LinkedArrayEnumerator.mDummyObject Is currentElement) Then
                Return currentElement
            End If
            If (mIndex1 = -1) Then
                Throw New InvalidOperationException("InvalidOperation_EnumNotStarted")
            End If
            Throw New InvalidOperationException("InvalidOperation_EnumEnded")
        End Get
    End Property

    Private disposedValue As Boolean = False        ' To detect redundant calls

    ' IDisposable
    Protected Overridable Sub Dispose(ByVal disposing As Boolean)
        If Not Me.disposedValue Then
            If disposing Then
                ' TODO: free other state (managed objects).
            End If

            ' TODO: free your own state (unmanaged objects).
            ' TODO: set large fields to null.
        End If
        Me.disposedValue = True
    End Sub

End Class