Possible Duplicate:
What's an actual use of variable variables?
OK, this question may look a little bit point-whoreish, but I'd really like to know: when are variable variables useful? I haved programmed in PHP for several years, but I've never used them. For me it looks rather funny than useful.
What are some real life examples of variable variables?
Update:
I'm really sorry about your votes. The linked 'duplicate' may be really a dupe except one thing: the examples listed there show me why not to use variable variables.
Never. This feature should be banned from the language as well as its other children diseases such as register globals, magic quotes, etc.