This is my idea of a minimal client-side router for Meteor.com (using Backbone.js and Handlebars).
To still be able to use sensible defaults from the browser I like to use the <a> tag for links (defaults like navigation using the <tab> key, having the correct mouse pointer w/o CSS etc...).
A click handler for all <a> elements on the page checks whether the href of the clicked element points to a local or external resource.
In the local case, it fires preventDefault() and uses the Backbone.js router to load a new page into our already-loaded single page web application.
In the external case, for demo'ing, a target attribute is added and the link is handled as usual (without preventDefault()).
To verify that this is using Backbone.js client side routing code you could kill your Meteor.com instance after loading the page. The internal links will still work.
Have a lot of fun!
Florian