Another excellent link from Al Vachris:

Bruce McPherson’s Site

This site is all about how to free your Excel data from your desktop and take advantage of web capabilities such as Docs, Maps, Earth , Gadgets, Visualizations and a whole bunch of other services . Along the way, you’ll see a few techniques, tips and tricks as well as fully functional sample applications in Vba and javaScript. All examples are downloadable here, and the code is unprotected and free for non commercial re-use.

Click to open site in new window

A random example from the site is the code below, which will let your computer quote Hamlet to you:

Public Sub say()
Dim TextA As Variant, i As Long
Dim sTerm As String, spv As Object

TextA = Selection.Value
Set spv = CreateObject("SAPI.SpVoice")

If IsArray(TextA) = True Then
For i = 1 To UBound(TextA)
sTerm = TextA(i, 1)
            spv.Speak sTerm
Next i
    Else
        spv.Speak TextA
    End If

Set spv = Nothing

End Sub

See http://ramblings.mcpher.com/Home/excelquirks/snippets/speak for more details, and download the sample spreadsheet below from Text2Speech.xlsb

Text2Speech.xlsb, download from the link above