Quickly check the magit-status of your favorite repos

Set up the magit-repo-dirs variable to point to your favorite repos:

(eval-after-load "magit" 
  '(mapc (apply-partially 'add-to-list 'magit-repo-dirs)
               '("~/dev/repo_a" "~/dev/repo_b")))

Now use C-u M-x magit-status and have magit prompt you to choose from one of your favorite repos.

(It works best with ido/iswitchb style completion for Magit.)