I've never, not even once, needed to write the pseudocode of a program before writing it.
However, occasionally I've had to write pseudocode after writing code, which usually happens when I'm trying to describe the high-level implementation of a program to get someone up to speed with new code in a short amount of time. And by "high-level implementation", I mean one line of pseudocode describes 50 or so lines of C#, for example:
Core dumps a bunch of XML files to a folder and runs the process.exe
executable with a few commandline parameters.
The process.exe reads each file
Each file is read line by line
Unique words are pulled out of the file stored in a database
File is deleted when its finished processing
That kind of pseudocode is good enough to describe roughly 1000 lines of code, and good enough to accurately inform a newbie what the program is actually doing.
On many occasions when I don't know how to solve a problem, I actually find myself drawing my modules on a whiteboard in very high level terms to get a clear picture of how their interacting, drawing a prototype of a database schema, drawing a datastructure (especially trees, graphs, arrays, etc) to get a good handle on how to traverse and process it, etc.