In emacs, I often find myself in a situation where I need to jump back and forth between various source files to various terminals. However, I feel like I do not have a good way to do this efficiently (and it stinks that you can only open one "shell" in emacs (shell, eshell, or term).
Moreover, I need an efficient way of juggling my terminals and source files.
What has worked for you?
Instead of having several terminal windows in emacs, I spawn a different xterm whenever I need a new terminal. This of course is bearable because I use a very lightweight terminal emulator (urxvt) which starts in under 0.2s.
Then I use my window manager to switch between them and emacs frames. A configurable window manager will have plenty of options to tune to switch between windows (extremely) efficiently. Inside emacs, I use windmove and ido-mode, and have bound to C-tab a function that switches to the last buffer (because I use C-x b in that fashion a lot).
So um, not sure how useful it is to you since it's quite different from your use pattern, but this is what works for me.
You can certainly have multiple interactive shells open. Try typing C-u M-x shell RET RET.
I usually do an an M-x server-start and then use emacsclient --no-wait to open files. I've aliased that to e with some embellishments so that it's a little more convenient.
I do all my work in a single terminal and just "throw" the files I want to edit into Emacs using e. Inside Emacs, I juggle around using iswitchb and it works just fine. YMMV.
You can use Emacs Lisp Screen, which emulates GNU Screen and provides easy key bindings to jump to and between a number of different shells.
You can have as many terminals and shells open at once as you want. Just use M-x rename-buffer to change the name of an existing *term* or *shell* buffer, and the next time you do M-x term or M-x shell, a brand new buffer will be created. In the case of M-x shell, a prefix argument will cause you to be prompted for the name of the new shell buffer, as offby1 noted.
A few years ago I had a job where I had to regularly log in to various production servers named "host01.foo.com", "host02.foo.com", etc. I wrote a little function like this one to make it easier to manage them all:
(defun ssh-to-host (num)
(interactive "P")
(let* ((buffer-name (format "*host%02d*" num))
(buffer (get-buffer buffer-name)))
(if buffer
(switch-to-buffer buffer)
(term "/bin/bash")
(term-send-string
(get-buffer-process (rename-buffer buffer-name))
(format "ssh host%02.foo.com\r" num)))))
Then I bound this command to (say) s-h (super H), enabling me to just type M-5 s-h. If I didn't already have a buffer named *host05*, it would start a new terminal emulator buffer, rename it to *host05*, and ssh me into host05.foo.com. If buffer *host05* already existed, it would simply switch me to it. Quite handy!