Portable Freeplane
Freeplane can run as a portable application from your USB stick.
Windows
#Download a portable apps platform and install it on your USB stick, #run the platform software from the stick, #Download a portable java, #Download FreeplanePortable_XX.paf.exe, #Install portable java and freeplane as explained here
If Freeplane does not detect Java automatically, edit:
PortableApps\PortableApps\FreeplanePortable\App\AppInfo\Launcher\FreeplanePortable.ini
and make sure the following path points to the correct Java installation:
FREEPLANE_JAVA_HOME=%PAL:PortableAppsDir%\CommonFiles\Java
Now you can start Freeplane from the portable app platform program menu and it should use the Java runtime from the USB stick.