I've gotten more and more into using the request scope for just about everything lately. Well, maybe not everything, but much more than I used to.
I usually start off with the following line of code in the application file:
<cfset StructAppend(request, url, "no")>
<cfset StructAppend(request, form, "no")>
This allows all url and form variables to be added to the request scope. For many applications, this is a nice convenience. There have been plenty of times when I come across a client that has variables either un-scoped (bad, bad, bad), or they might get the variable from the form or url scope. This solves that problem.
Example: A form submits to a page that shows a report. The report expects many of the variables to come in the Form scope. However, they also have a download link that passes everything in the Url. Now, you can always have a few lines at the top of the page like this:
<cfset form.myVariableName = url.myVariableName>
But you would have to do this for every variable that could possibly be passed. With the request scope, you can set it in one place, and then reference it.
Another convenience item I like is adding the dsn name to the request scope as well. Again, in the application file.
<cfset request.dsn = "MyDatabaseName">
The greatest benefit with this, is that now this one variable - "request.dsn" - can be used in CFCs, CFMODULE, Custom Tags, etc. I don't have to pass the name of the dsn variable in the arguments scope to a CFC, or attributes scope for a custom tag, as I have seen others do. Very nice.
Of course, there are always circumstances where you may want to have the dsn name passed in, but for the fast majority of circumstances, I gladly omit that variable and reference my request scope!