mapquest_layer

gistfile1.js

var map = new L.Map('map');
var mapquestUrl = 'http://{s}.mqcdn.com/tiles/1.0.0/osm/{z}/{x}/{y}.png',
subDomains = ['otile1','otile2','otile3','otile4'],
mapquestAttrib = 'Data, imagery and map information provided by <a href="http://open.mapquest.co.uk" target="_blank">MapQuest</a>,
<a href="http://www.openstreetmap.org/" target="_blank">OpenStreetMap</a> and contributors.
var mapquest = new L.TileLayer(mapquestUrl, {maxZoom: 18, attribution: mapquestAttrib, subdomains: subDomains});