I dont like to pay for software so I'll give you some opensource.. :-)

OpenOffice's Draw can draw simple flowcharts.
http://www.openoffice.org

Dia is another alternative that I've used to create quite a few flowchars/computermaps...
http://www.lysator.liu.se/~alla/dia/

Both program works in at least Linux and Windows (I only use linux...).

Fredrik