any one knows of a free scheduling twitter site

there were a couple of site that would let you schedule random tweets in advance now its seem you have to pay per month I have about 50 accounts and don't want to use twuffer to schedule one by one can any recommend any other sites
Regards
Suave

Any one?

I'm not in touch with many of those services, but socialoomph should offer tweet scheduling for free if i'm not mistaken.