This site is in German Language, but there are some very interesting pictures for Rolleiflex users.
Special Edition Rolleiflex 2.8 GX. Here too.
More from Vivian Maier.
More from Eva Besnyö.
Short History of Rolleiflex.
Rolleiusers group at Yahoo.
Rolleiclub is as far as I know the biggest Rolleiflex database.
I strongly recommend these two sites (here and here) with pictures of Vivian Maier.
This lady spent a lifetime shooting people randomly in the streets only for her own satisfaction. She never bothered to show her photos that were discovered almost accidentally. Lucky us!