Isolate domain from url string

Is their a function to do this?

[rover]

Does anyone know if there is an existing function or easy way to take a url string like:

[example.com...]

and return just the main part of the domain:

example.com

I've been searching around, but can't seem to find anything. Any ideas or hints in the right direction would be much appreciated...

[jatar_k]

what about using parse_url [ca3.php.net]

[rover]

Thanks!