Mailing List Subscription "Widget" for Group = "Mailing List" and Visibility = "Public" (Create & Manage)

Scenario :
Some organization use CiviCRM as a back-office CRM but they don't have it integrated with the front-end website using the standard CMS like drupal, joomla or wordpress.

Issue :
The organization that want to manage Email Subscription List for Newsletter using CiviCRM have difficulties to integrate with their website technology.
For this reason they end up creating a Simple "URL" that will redirect the user to the public page of CiviCRM to Subscribe the new email to the Mailing List.
ex. http://drupal.demo.civicrm.org/?q=civicrm/mailing/subscribe

Request :
There is a need to have a "Widget" that can be "Embed" into any Website that will allow to "Subscribe" to 1 or more Group with Type = Mailing List & Visibility = "Public".

I'm not sure where this widget should be Managed but you should add to the menu
"Mailing List Subscription Widget" maybe inside "Mailing"

Additional :
I really liked the Widget for "Contribution" and you should keep the ability to "Edit Widget Colors".

Conclusion :
I'm suggesting this new feature because I see an needs for it and I will be using this feature if available.
If there is an alternative to the "widget idea" can you please comment on this ticket and let me know what is the "workaround" ?

Thank You.