Hm, the only website I know is
Rent my DVR , although it works online with a download-client instead of sending tapes.
Well, recording a tv-show for (your own!) personal use is legal, but distributing is not. Even the use of colleagues, friends or co-workers for recording a tv-show is not legal; although there do exist broadcasting networks who allow this, see
FOX.com . Regarding Rent my DVR and all shows offered via file sharing networks, I suggest you read this news.com article:
Supreme Court rules against file swapping .