Gridster is an impressive jQuery plugin to develop iGoogle-like multi-column grids that can be drag 'n' dropped and re-ordered.

The plugin only requires jQuery (no jQuery UI) and can convert any given HTML structure into the widgets of the grid.

And, we are not limited with the elements loaded initially but can add and remove new ones dynamically.

Gridster.js

The number of columns/rows, margins between items and required styles being generated automatically can all be set.

Also, there callbacks on every level and a .serialize command returns the positions of all the widgets anytime we want.