Plug-in for creating multiple users and posts for testing purposes

We are developing a new international website based on WP/BP and are now looking for a plug-in to automatically create multiple fake users. Each fake user should create multiple fake posts on their on blog and fake posts in groups, forums etc.

We are interested to see how the website looks with many users and many post active. I can remember reading about a plug-in doing this – but after doing a lot of searching without success I’m hoping anyone here have the answer?