createComponent is 18 lines of JavaScript that puts a lean and enjoyable interface on top of React's somewhat clunky and non-JSX-hostile API.

reactorama.js

// Most components are defined fully by their render function,
// and all they need to access is the props

var myComponent = createComponent(function (props) {
  return React.DOM.h1({}, "Hello " + props.name);
});

// ...which can be done very succinctly with ES6:
const {h1, div} = React.DOM;
const myComponent = createComponent(({name}) => h1({}, `Hello ${name}`));

// You can also define the full object if you need to implement other hooks:

var myOtherComponent = createComponent({
  shouldComponentUpdate(newProps) {
    return newProps.data !== this.props.data;
  },

  render({name}) {
    return h1({}, `Hello again, ${name}`);
  }
});

// Use:
var appData = {name: "Some Programmer"};

React.render(
  div({}, myComponent(appData), myOtherComponent(appData)),
  document.getElementById("app")
);

// All you need is this little helper (ES5, could be simplified with ES6)

function createComponent(render) {
  var def = typeof render === 'function' ? {render: render} : render;
  render = def.render;

  def.render = function () {
    return render.call(this, this.props.data, this.props.children);
  };

  if (!def.getInitialState) {
    def.getInitialState = function () { return {}; };
  }

  var component = React.createFactory(React.createClass(def));

  return function (data) {
    return component.apply(this, [{data: data}].concat([].slice.call(arguments, 1)));
  };
}