In Views, how to allow users to toggle between a grid and list? I have a view that returns a 4 column grid view.  The client wants to be able to toggle between grid results and teaser results by clicking on an icon.

Does Views handle this naturally?  Do I need to utilize AJAX?
If you want to do something like this,


then you can use QuickTabs Module

So, here user can switch from TAB-ONE to TAB-TWO .. so on .. 

To implement this, first you have to create View-Blocks and then you have to create Quick Tabs by using QuickTabs Module

Here is one Video Tutorial to create QuickTabs.