Example of using Meteor.methods() and Meteor.call()

gistfile1.js

if (Meteor.is_client) {
  Template.hello.greeting = function () {
    return "Welcome to XYZ.";
  };

  Template.hello.events = {
    'click input' : function () {
      // template data, if any, is available in 'this'
      if (typeof console !== 'undefined')
        console.log("You pressed the button");
      console.log(Meteor.call('test', 1, function(e, r) {
        console.log('e', e);
        console.log('r', r);
      }));
    }
  };
}

if (Meteor.is_server) {
  Meteor.startup(function () {
    // code to run on server at startup
    Meteor.methods({
      test: function(arg) {
        console.log('test'+arg);
        return 'test'+arg;
      }
    });
  });
}

@brunodb3 Methods don't have to be defined inside Meteor.startup():

Source: http://meteortips.com/first-meteor-tutorial/methods/