AngularJS Example:

HTML

<link rel="stylesheet" href="http://twitter.github.com/bootstrap/assets/css/bootstrap.css">
<div ng-app>
  <div ng-controller="TodoCtrl">
    <p>{{meuValor | currency:'R$'}}</p>
    <p>{{meuValor2 | currency:'R$':2}}</p>
  </div>
</div>

JavaScript

function TodoCtrl($scope) {
  $scope.meuValor = 10.3;
  $scope.meuValor2 = 10.345897;
}