Flash was the tool for creating interactive maps where we can hover or click any region and see details about them.
jVectorMap is a jQuery plugin for creating such interactive maps very quickly.
It uses SVG as the map format and there are various ready-to-use map files provided. Also, using a vector graphics editor (like Adobe Illustrator), we can draw anything (like the map of a shopping mall), export it to SVG and add interactivity to it.
There are options provided for customization (colors, opacity, etc.) and callbacks exist on every level.
P.S. There is also a Python converter for creating map data from GIS files.
P.S.2 If you are in search of vector freebies, checks these vector images.
Compatibility: All Major Browsers