jHERE - Maps Made Easy. IkiMap | Create and share your maps. Ziptastic. jQuery Map Marker Plugin | Welancers. jQuery Map Marker Plugin makes it easy to put multiple markers on Map using Google Map API V3.
Map Marker is very useful when you have a list of data & you want to show all of them on Map too. Like most of the jQuery plugins, this plugin is very straight forward to setup. It has some nice options & uses JSON formatted data for every Locations. Also make note that you must have to pass the Location values using Lattitude & Longitude co-ordinates of the that Location (due to Google map API limitation).