Before we started using Eloquent all models extended MY_Model which had some convenient functions such as dropdown(). So I was looking for the cleanest way to do that in Eloquent. That is why I started trying the lists() method. By the way, I does still exist on L4.

See here
https://github.com/laravel/framework/blob/master/src/Illuminate/Database/Eloquent/Builder.php#L36

The problem is the lists() method has to be called from a QueryBuilder not a Collection.

I think in general, Pyro models should return collections because they have those cool convenient built in methods.

So we don't have to do getGroupOptions(). We can just have getGeneralGroups() return a collection and use the toArray() method to format the options for dropdowns. I think this is the cleanest way.

Example
```php
$groups = Group::getGeneralGroups();
$group_options = $groups->toArray();
```
I tested this and works perfect. I have it working with Navigation.

I will have the PR soon.