Delete all contacts

[-Ollie-]

Hi,

I have a Samsung galaxy S and I want to delete all the contacts I have on this phone. All my gmail contacts got sync on my phone by mistake, and I don't wan't to do that.
The user guide does not describe how to perform this, and I am unable to find out how to do this when "playing" with the different options in the phone.
Any hint?

Thanks
Ollie