Session file location?

[Ash]

I'm using sessions to check that users are logged in. I need to check that it's being updated, but can't find the file.

I've just looked in the php.ini and it doesn't have a session.save_path in it, and I've tried looking in obvious .tmp places.

Does anyone know where the session file is likely to be stored on an XP machine?

Thanks,
ASh