In a way, these can be called separate productions of the anime Gurren Lagann, as well as they can be considered as extras for the people who have enjoyed the show, either way it will be great to have them here
Gurren Lagann Parallel Works
Gurren Lagann Parallel Works 2
Tengen Toppa Gurren Lagann Kirameki Youko Box: Pieces of Sweet Stars
Viral's Sweet Dream

Looked them up, and found a very great torrent that holds them all here(I sure do hope it is still being seeded)

They should be up now.

danke schön ^_^