Snap

interact.js is a standalone javascript module for handling single-pointer and multi-touch drags and gestures with powerful options such as inertia and snapping to grids or custom coordintes.   interact.js - Features: inertia snapping to a grid, custom anchors or paths. cross browser and device, supporting {Chrome,Firefox,Opera}' '{mobile,desktop}', ' and Internet Explorer 8+ interaction with SVG elements being standalone (not yet another jQuery plugin) introducing 0 additional DOM elemen

jQuery.panelSnap is a jQuery plugin that provides snapping functionality to a set of panels within your interface. It snaps to blocks of content after scrolling.  

JavaScript Kinetic Scrolling is a javascript scrolling plugin that supports touch and drag scrolling, horizontal swipe and snapping to grid.  

windows is a handy, loosely-coupled jQuery plugin for full-screen scrolling windows.  This plugin simply opens up a handy API for position management, provides callbacks, and will allow for window snapping. No CSS is applied to the callee.