Anybody planning on building an adapter for Nikon might want one of these... Most of you probably know what it is anyway. I just found this seller with a few of them (I bought one already) and thought somebody else might be interested: http://cgi.ebay.com/Nikon-BR3-Macro-Adapter-Ring-F-Mount-New-Film-Digital_W0QQitemZ7587028314QQcategoryZ30059QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

Just a heads-up. Beats spending $30+ at B&H.