TheFolderSpy is a folder monitoring utility that can monitor several folders simultaneously.
I didn't check this out for portability. Someone may want to do this if they think it's worthwhile. It's very tiny and works great on multiple folders.
Developer Site: VenusSoft Corp
Downloads:Released Version (2010)Beta Version (2013)
Info below from VenusSoft:
-Small size (60 KB download).
-Simple to use.
-Portable (No installation, carry in your thumb drive).
-Monitor any number of folders in real-time.
-Execute a file when a change is detected(plays wav files, executes other files).
-Fully automated (Run and forget).
-Monitor many types of changes: Creation,Deletion, Attributes changes, Access date, Filesize changes etc.
-Auto start (optional).
-Can write logs.
-Monitor specific files in a folder.
-Send EMAIL when a change is detected. [custom SMTP also available!]
-And many many more...