Modules Anywhere Allows you to Place Modules not just in the sidebar, but in content, or just about anywhere!
On almost every site I create, I've used NoNumber's Modules Anywhere because it's such a useful extension. For me, I generally will place modules inside the content to display ads or other information.
To install Modules Anywhere, log into your Joomla! control panel and go to Extensions > Extension Manager and search "modules anywhere".
Just install it and then go to your plugins by going to Extensions > Plugin Manager
You want to make sure that both the button and system plugins are enabled.
In your content editor screen (where you create your articles), at the bottom, you will see a new button that will allow you to insert a module into content. This inserts a module, but not a module position, so it is specific to just a single module right now.
When you click the insert module button, you will see a popup come up allowing you to select a module you wish to place into the content.
Just choose the module that you wish to display in your content, and you're done!
For more information on Module Manager, Please head over to NoNumber's site. Modules Anywhere comes in two versions, both a free and paid solution. The paid solution offers you one year of pro upgrades, parameter overrides, embed in div via editor button and advanced security control. The module is only 25 Euro, and well worth the price.