Web-based IRC clients have existed for a long time. To use them all you have to do is point your browser at a website. The usernames assigned by these clients

Web-based IRC clients have existed for a long time. To use them all you have to do is point your browser at a website. The usernames assigned by these clients are usually something like "guest0", "guest1", etc. That's probably anonymous enough. You could connect to any number of public IRC servers already set up all over the world. Then simply join the channel of your choice. No bots necessary. As far as invitations go and teaching people what to do, you're going to have to do that any way. With existing web-based IRC clients it's as simple as pointing your friends/colleagues to the website and telling them to join channel #whatever.