In a recent project I needed a way to quickly grab user profile information and include it in the context of a custom application for SharePoint. I decided that I wanted to make use of templating to render the HTML for the user profile, so this lead me to look up the various jQuery templating plug-ins. I was a bit disappointed to see that the Microsoft stubs have been abandoned as a lot of my initial searches returned examples using this plug-in.
However, I discovered a new templating engine that seems to be showing a lot of promise called JSRender. This provided some very simple semantics to create a reusable template. When coupled with SPServices and a little bit of creative code parsing, you can quickly declare reusable templates for client side scripts in SharePoint.