I'm currently working on a web application and the powers above have decided that overriding the browser's right-click menu with our own application-specific one is the way to go.
I totally disagree. I feel that when someone is using a web browser they have certain expectations about what should happen when they use the right-click functionality of a pointing device, and violating these expectations by purposefully supplanting this functionality is very disconcerting (annoying?) to the user.
What do you think? Have you ever seen right-click done well in a web app? I mean in a way that you actually thought, "Yes, this right-click functionality was a great decision."?
In general I don't aggree with "right click menu" in web app but if it is a must you have to add an alternative method working side by side with the context menu and don't depend on the user experience.
Yes: you should have context menus. Actually, you don't have a choice. The browser is going to give you a right click menu but the only context will be for a web page. So when you click on an order line, say, the browser will offer you such actions as Back, Save As, View Source and Print. You may not be happy with these. So the question is: do you want to override these with something more suitable for the context? As web apps become more like desktop apps the answer will increasingly be yes.
I think it is a bad idea to have a right click functionality.
Shog9's answer is the best direct answer to your question, but another reason to avoid contextual menus in web applications is that it is a golden opportunity to break away from the use of contextual menus.
Most Windows and *nix GUI applications rely heavily on contextual menus to implement a large part of their functionality. One reason that the Mac OS has traditionally been praised for high usability is that true menu options and toolbar elements have been favored over contextual menus, which quickly become a ghetto of nested lists (especially if other applications are allowed to embed functionality).
Web applications are a breath of fresh air to UI designers precisely because the interface must be usable and powerful without the use of the right click menus. Furthermore, casual users are surprisingly not put off by new UI paradigms in web applications, whereas experimentation on the desktop is often anathema.
The age of the in-browser application thus is a great opportunity for developers to rethink UI paradigms. Right click menus are a cop-out on the web.
No, and it will never really work anyway since the user can prevent your attempts to over-ride it.
It depends on the type of app. I always thought this was a bad idea, but web apps are getting closer to desktop apps all the time. So I asked the master of usability (Nielsen) and surprisingly, he's all for right-clicks!