Organigram

Hello,

I just wanted to draw organigram in Keynote and I found that there are no tools for that, not even simple connectors... is it true? if anyone does charts like organigram on a Mac - how do you go about it (without recourse to expensive professional software packages) - only Powerpoint for Mac? I would appreciate links to any non-expensive/free products for a Mac. Many thanks.

Sergei