Assuming you have already searched for this and found loads. Which ones have you tried out, and what was wrong with them that has lead you to ask here?
Tim Driven Development
Joined: Apr 08, 2004
Already gogled.... Not happy with Jude UML tool and MS Visio free version( need to burn and install). Looking something free UML tool and flow Chart tool.
Joined: Mar 22, 2005
If you don't tell us in which way those were not to your liking it is going to be hard to advise which ones might be better. Or if those requirements are best met by a commercial tool. For starters I would advise to try a dozen more or so; searching for "free UML and flow Chart tool yields 300K+ hits, after all, there's bound to be more tools available.
Still not giving us much to go on. But anyway, I've found Gliffy to be decent enough. Have also drawn plenty of diagrams with Dia which is very simple. Never used, but have heard great things about, OmniGraffle. The last one is probably not free, and only available for Mac but it looks extremely rich in features, if that's what you're after.