Even better than ^Z to run tests is temporarily mapping a key combination to run them. For instance, I'll do :map ,t :w\|!rspec<CR> which lets me type ,t in command mode to save the file and run the tests. Vim will show you the output of your command and then wait for you to press a key to return to Vim.
Actually, there are a bunch of plugins that will use a subshell to run this, and then bring it up when it's done so you can keep working while the tests run.
Not so important for a quick script but if your tests/compiling takes a few minutes, totally worth it.
