For those that have been working with Flex, or at least just reading some of the press, you will know that Adobe also puts out a very nice IDE called Flex Builder. While Flex Builder gives you a lot of time saving features, it is not strictly necessary for deploying Flex applications. It is possible to compile your Flex applications from the command line using the free compiler that is available for Flex.
In doing some digging for Ant related materials this afternoon, I came across a project called Flex2Ant which gives you the ability to "add a specific Ant task to the Ant installation that is part of the Eclipse IDE" and enable you to compile your Flex applications within Eclipse and without Flex Builder.
I have not tried this out yet as I like some of the other features of Flex Builder, but I thought it was another interesting use of Ant.
If you want to check it out, take a look at http://www.flex2ant.org/.