retty project is a utlity that can attach to processes running on another terminal.
You can run retty on it, do your work, and detach application back again. Its advantage over screen is that you don't have to run the processes on retty in advance.
· Attaching less doesn't work, we have no idea why yet
· The new terminal does not become the new controlling terminal for the application (this seems to be unfixable without messing with the kernel, unfortunately) - that has all sorts of negative consequences, most importantly: /dev/tty is not the right terminal, leading many applications (e.g. mutt) to misguess window size; pressing Ctrl-C does not deliver a signal to the application, so you can't break it this way (send SIGINT manually)
· You can attach only a single process, so if you want to resume editing a mail in mutt, first you need to attach the editor, then when you are finished quit it and attach mutt