Who knows Tsutomu Nihei???the author of Blame! and Noise??? it seems that not many people know him...if you do please answer this post!!

I see that also here no-one know Nihei....well he's the author of Blame!! and was formerly an architect before joining Kodansha, first by being an assistant to Tsutomu Takahashi (Jiraishin, Tetsuwan Girl are a few of his mangas) and after by starting his own series in 2000. Blame! is now finished, it's made up of 10 volumes and what is very particulare about Nihei is how it's not the characters (who don't speak much, and sometimes there are something like 40 pages without speaking...) but the enviroment who is very important. The story is very difficult to understand as not much is explained. It's not even clear where or when the story begins or ends...

how many mangas has he worked on?

not many..as far as I know only three: Noise (his first one), Blame! (his most populare one) and Biomega, his new one, which is for the moment made up of only one volume (for the moment...)