I personally like to put out most of my business logic (services, models, etc.) into its own namespace. I'll then inject that logic into the controllers, and use it as needed throughout. That keeps my controllers really simple, able to properly handle exceptions, and easier to understand.

Folder structure is something like this.

- app
    - controllers
    - Acme
        - FooService.php
    - (other folders)

Then the controllers look something like this.

<?php

use Acme\FooService;

class HomeController extends BaseController
{

    protected $fooService; // This handles services specific to foos.

    public function __construct(FooService $fooService)
    {
        parent::__construct();

        $this->fooService = $fooService; // Now we can use the fooService's logic.
    }

    public function index()
    {
        $foobars = $this->fooService->getActiveFoobars();

        return View::make('foobars.index', compact('foobars'));
    }

    // ...rest of controller.

Let me know if I haven't explained the ideas behind this enough! Again, this is normally how I separate out my business logic in a reusable way. There are plenty of other ways to do what you're looking for, so I'm sure you can keep looking around to find a way that will work best for you.