Shoutbox

What I meant actually was that you could 'blocks fishing', that is changing display picture, nickname, personal message, and do other tricks that might trigger a response, random at a certain interval (let's say 5 minutes, or 15, or 30...) and if you get any response && the contact's status is offline you get a message, but you also have an option to just track your list, on response, see if contact is offline, but change nothing.
You could then use a popup generator to change your nickname into <name>, I know ur online, and then block/unblock 1, 2 or 3 times to get that persons attention.

I know I'll be marked as a n00b or newbie for certain now, but I guess many people would like a script like this actually...

Also I've noticed if the contact has WLM he/she can talk while Appearing Offline, but also receive messages. I don't know, but maybe sending /ping, and the contact has Plus! would result in a pong?

EDIT: I sort of realise a session has to be closed in order to be reopened, and if the contact just blocked you you have to wait for the session to be closed, and so not change anything actually... That may explain why you didn't get any notifications when you blocked the other contact...