http://lifehacker.com/5149483/lovely-charts-creates-polished-diagrams - online flow-chart generator
LucidCharts has some nice free-and-better-if-you-pay online flow (and other) chart generators.
Venn diagrams - not the one I used a couple of weeks ago (and can’t find back), but okay
http://stackoverflow.com/questions/347929/online-uml-guide
Hello, lazyweb are there any online UML generators? I can’t find any....
http://stackoverflow.com/questions/15376/whats-the-best-uml-diagramming-tool
which pointed me to http://en.wikipedia.org/wiki/List_of_UML_tools
http://stackoverflow.com/questions/390438/good-free-uml-tool-for-java-eclipse
http://www.websequencediagrams.com/ - no review