This code will make a tray icon blink whenever someone speaks on ERC. It’s got a C part and an elisp part. The C part only runs under unixes, and you need gtk to build it. Both codes are very simple, feel free to extend it and send me patches.

C part : tray_daemon

The code is available at , see installation instructions there

Elisp part

Add this to your .emacs :

;;list of regexpes ignored by tray icon
(setq erc-tray-ignored-channels '("something" "something_else")
(defun erc-tray-change-state (arg)
  "Enables or disable blinking, depending on arg"
  (if arg
       "echo B > /tmp/tray_daemon_control")
     "echo b > /tmp/tray_daemon_control")))
(defun erc-tray-update-state ()
  "Updates the state of the tray icon according to the contents
of erc-modified-channels-alist"
  (unless erc-modified-channels-alist
    (erc-tray-change-state nil))
  (let ((filtered-list erc-modified-channels-alist))
    (mapc (lambda (el)
	    (mapc (lambda (reg)
		    (when (string-match reg (buffer-name (car el)))
		      (setq filtered-list
			    (remove el filtered-list))))
    (when filtered-list
      (erc-tray-change-state t))))
(when window-system
  (add-hook 'erc-track-list-changed-hook 'erc-tray-update-state))