explore-theme.el

(defun use-theme (theme &optional no-confirm no-enable)
  (interactive
   (list
    (intern (completing-read "Load custom theme: "
  		     (mapcar 'symbol-name
				     (custom-available-themes))))
    nil nil))
  (progn
    (dolist (curtheme (custom-available-themes))
      (disable-theme curtheme))
    (setq used-theme theme)
    ;; todo add to mode line
    (load-theme theme)))  


(defun following(n l)
  (if (eq n (car l)) (car (cdr l)) (following n (cdr l))))
  

(defun cycle-theme ()
  (interactive)
  (progn
    ;; hack: append car of list to list to allow it to cycle
    (let ((hacktheme (append (custom-available-themes) (list (car (custom-available-themes))))))
      (use-theme (following used-theme hacktheme)))
    ;; yuck! I'm still learning mode-line-format. important thing is appending (list (symbol-name used-theme)) to the end
    (setq mode-line-format (append '( "  =^..^=" mode-line-front-space mode-line-mule-info mode-line-client mode-line-modified mode-line-remote mode-line-frame-identification mode-line-buffer-identification "   " mode-line-position
                                      (vc-mode vc-mode)
                                      "  " mode-line-modes mode-line-misc-info mode-line-end-spaces) (list (symbol-name used-theme))))))

Thanks for this -- use-theme is great! It's really nice not having color theme artifacts after switching.