You could try for the Blu-Ray player - but I believe the additional flash memory historically holds BD-Live content downloaded through the player and stored on thumbdrives for models that don't have additional memory capacity.
The TV, as it stands, would not perform this function.
You might check out this thread - someone noted that a call and minor change helped, although I can't confirm or verify that information:
I have the BD5900 and C8000 LED TV, both of which have USB ports for flash memory. When I try to use Vudu for HDX download there are frequent pauses to buffer the video stream. Using the "Internet@TV" setup, testing both BD player and TV shows average hard-wired internet connection is between 4.5 and 5.5 Mbs. I want to know if adding addtional memory with a blank USB flash drive (e.g. 1 GB) would help create a larger buffer and improve streaming.