I've used modelio and StarUML. They are both pretty good, but each one has its own shortcomings. I haven't used DIA, but have heard lots of good things about it. I may give it a try.
Hmm... I think most people in the business would be able to differentiate between a web app and a web site. It's just that sometimes web apps may also involve a web site, that's all!
I have been using Agile methodologies (in particular Scrum) for software development for many years and I can tell you that it if it is applied correctly it works for small and LARGE projects alike.
And, this is not some theoretical claim, it's based on real-life experience!
Derek, I haven't read the other one, but the book Agile Software Engineering with Visual Studio by Sam Guckenheimer and Neno Loje is indeed very good and I would also recommend it! There are actually many good Agile books out there, but the best way to learn it is by doing it. Succeeding with Agile ...