jQuery Geo is a plugin that obvious runs on jQuery and provides and easy-to-use API for actions related to map or geolocation. Using the open source map servers (Open Street MAP, WMS and Esri ArcGIS) to get map data, jQuery Geo can show mapping data and handle direct user interaction with the map but also use geospatial functions like calculating bounding boxes, mesure distance between geometries and other cool stuff.
jQuery Geo also provides mobile support, thus the maps that are created are mobile-friendly and has a lot of built-in methods for customization. The plugins comes with a well-documented page and with a large number of examples.
jQuery plugin for map actions