Do I need to create a mu-plugins folder for multi-site/buddypress?

Do I need to create a mu-plugins folder for multi-site/buddypress? I am creating a new site and I have installed wp 3.0.1, activated mutli-site, and installed buddypress. All of that seems to be working fine. I also installed the buddypress sidebar plugin automatically and it installed to the plugins folder. Now I want to install the ads widget and it says to install it to the mu-plugins folder. There is no such folder. Do I need to create that folder in wp-content now?