_blogroll is a list of 2-element tuples, each containing a title and a list of name/url pairs.
A minimal blogroll will look like this:
_blogroll = [ ( 'title', [ ( 'link 1', 'http://link1.com' ), ( 'link 2', 'http://link2.com' ), ] ), ]
A blogroll with two blocks looks like this:
_blogroll = [ ( 'title 1', [ ( 'link 1', 'http://link1.com' ), ( 'link 2', 'http://link2.com' ), ] ), ( 'title 2', [ ( 'link 3', 'http://link3.com' ), ( 'link 4', 'http://link4.com' ), ] ), ]
See http://www.pycs.net/users/0000062/ for what this looks like when rendered.