This is a QGIS plugin to backup a QGIS layer by creating a compressed archive (zip) of the data files corresponding to the selected layer. The plugin will search for all files in your data file directory that has the same name as your data file, independently of the extension. The compressed archive will be saved in the same folder as original data file with current datetime stamp appended to the file name.
More info in the wiki.
Basic instrucions here.