I usually cheat by calling the 'ls' or 'dir' command (depending on OS) with the appropriate options inside of backticks. Since I primarily work in Windows, sometimes I'll bust out the Win32::File module to test the returns of readdir to determine what's a file and what's a directory.

Instincts tell me that there's probably a 'better' way to do it, but I haven't found it yet and have been too impatient to look for it when I needed to do something like this.