Hello,
I have noticed the idea, and think the theory of this is good, however as this relies on the goodwill of the people involved, I'd like to put a few suggestions?
Timezone and Availability sensitive: Games like WoW have scheduled raid events, and players won't want interrupting during those. Having the ability to set when you are 'available' to help would be very useful. Also priortizing perhaps on who lives in what timezone, so you can target alerts to an area where more players are online at once. Be able to sign in and out easily, a tick box or something.
Mobile App: This is a little ambitious, but let's see if I can explain what I'm thinking.
If a "IRL Responder" creates an account with yourselves advising when/where they would be willing to respond to events and such, with the positive responses recieved they could build up "credit" eventually to use in various games that co-operate?
Also, as a working proof of concept it could be used for showing the interest the gaming community has, and a selling point to games you are interested in getting such access to.
Having an app that can recieve a notification to your device like the the
http://hisz.rsoe.hu/alertmap/index2.php team do, along with a customisable profile of when you would like to recieve notifications, and the area you're in - you don't want notifications at night for example. Also with options to download image content over wifi / data as some people's mobile data plan may suffer with this.
There are a few holes in the idea above, it's literally nothing more than theorycrafting and whole cloth at this stage, but I do like the principle of what you are trying to do.