Program that can post to multiple program blogs at once?

I am looking for a program where I can insert hundreds of tumblr accounts and publish posts to every tumblr account.

You can use RankerX to create/insert hundreds of Tumblr accounts and publish posts to every Tumblr accounts. I use RX as part of my Web 2.0s(tumblr, wordpress, jimdo,...) and have had good results so far.