BuddyPress.org

Have a look at wp polls instead, in my opinion a very nice and customizable poll system. It includes a widget.

https://wordpress.org/extend/plugins/wp-polls/

Edit: I just found that automatic install of the plugin does not seem to work. However install and using it right out of the box works fine for me when uploaded by FTP, in WPMU 2.9.2 with BP default theme. There are also some theme related issues: https://wordpress.org/support/topic/358769