I have an idea for a service that I think would be neat, but I don't have the resources to make it. So I submit this into the ether for someone else to make. The idea is anonymous ad-hoc email groups, sort of like wikis for email groups.
It would be sort of like mailinator, where email addresses are created on the fly. Only instead of those emails just sitting on the server, they would go out to anyone subscribed to the group, which could be done as simply as sending an email to the group's address or typing the name of the group into a simple text box.
Such a service could be used to facilitate ad-hoc discussion groups around any topic. In this post, for example, I could encourage readers to send an email to firstname.lastname@example.org (available) if they'd like to talk about this idea. If they already had an account under the email address they sent from, they would be automatically added to that group. If not, they'd get a response with a password they could use to login to a website, where they could type any number of email addresses into a list and subscribe to any group they wanted.
I'm currently working on dynamic email addresses at work (e.g. department or location-based email groups that auto-update based on our employee database), so that's what got me thinking about it. I only have a few vague ideas for use cases, but that's part of why I like the idea so much. It's such an open-ended platform that it would encourage others to experiment and find innovative new ways to use ad-hoc email groups.
Like any communications system, the big worry would be spam. But I think a simple registration process and no one really knowing how many people are subscribed nor what the groups even are, would cut that down significantly. The service would require a custom-built email server, though, and one that could process a lot of email very quickly. So I think one of the bigwig web players should do it. Or at least quickly buy up someone else who does it. In any case, I'd like to play with it, so I hope someone will make it.