Shows how to work around dateline issues, by wrapping the dateline on a number of layer types.
This is an example that shows wrapping the date line. Wrapping the date line is an option on the layer.
You can do it with a 'Layer.WMS' or a 'Layer.MapServer' layer.
    var mapserv = new OpenLayers.Layer.MapServer( "OpenLayers Basic",
                "http://vmap0.tiles.osgeo.org/wms/vmap0",
                {layers: 'basic'},
                {wrapDateLine: true} );