Show several modules as one (for example with single border around them) with Unified Module Chrome module.

What this module is about

Joomla! content management system has some conventions how usually templates are built. One of them is providing chrome around a module within some locations such as box with borders (often with rounded corners)

Also good for

It can also be very useful with several Tab implementations (such as ja_tabs from joomlart) where each module occupies a single tab but you want several module within a tab.