def METHOD_NAME(defaultExt = '*.tif'):
    from PYME.IO.dataExporter import exporters
    wcs  = []
    exts = []
    defIndex = 0
    for i, e in enumerate(exporters.values()):
        wcs.append(e.descr + '|' + e.extension)
        exts.append(e.extension[1:])
        if e.extension == defaultExt:
            defIndex = i
    fdialog = wx.FileDialog(None, 'Save file as ...',
            wildcard='|'.join(wcs), style=wx.FD_SAVE)#|wx.HIDE_READONLY)
    fdialog.SetFilterIndex(defIndex)
    succ = fdialog.ShowModal()
    if (succ == wx.ID_OK):
        fname = fdialog.GetPath()
        #we decide which exporter to use based on extension. Ensure that we have one (some platforms do not
        #automatically add to path.
        if os.path.splitext(fname)[1] == '':
            #we didn't get an extension, deduce by looking at which filter was selected
            filtIndex = fdialog.GetFilterIndex()
            fname += exts[filtIndex]
    else:
        fname = None
    fdialog.Destroy()
    return fname