In my Meteor app I find myself writing a lot of things like:
Templates.myTemplate1.isCurrentUser = function() {
return Session.get(\"isCurrentUser\");
};
Building on @cioddi's answer, as you can pass parameters to the Handlebars helpers, you could make it a generic function so that you can easily retrieve any value dynamically, e.g.
Template.registerHelper('session',function(input){
return Session.get(input);
});
You can then call it in your template like this
{{session "isCurrentUser"}}
Note that the auth packages come with a global helper named CurrentUser that you can use to detect if the user is logged in:
{{#if currentUser}}
...
{{/if}}