When writing web applications, ultimately, you probably want to look at performing load testing. This is most easily done by an application, running a script, and pretending to be a number of users.
Of course, if you’re doing something like, say, creating nodes in some sort of a hierarchy (think messages, or files/folders), then you might need to do some stuff before performing other operations – like see if your node was created, get its ID, that sort of thing.
So here’s my thought – make that easy. Put things like ‘New Node ID = ‘ into HTML comments near the top of the page. That way, it should be possible to find and read them with many of these tools.