Here's something I would pay money for and maybe other publishers, as well.
Through WindyCitizen.com, I get about 40-50 press releases a day trying to get one our writers to cover some event or celebrity appearance in Chicago.
This is absurd considering our site is all user-generated content. But we're on lists somewhere and so the PR industrial complex thinks we want to hear about all their fake news. It's really annoying.
I would pay money for a gmail plugin that lets me specify the e-mail addresses of X PR people, and then responds to their press releases automatically with an e-mail from me telling them what it will cost them to buy advertising on our site that promotes the event they're touting.
If they're going to spam me, I would like to be able to spam them.
Most of them will just ignore the e-mails, but they'll get the picture eventually.
Meanwhile, some of them will convert into advertisers. If I pick up $1500/month worth of advertising from this tool, I would gladly pay $30-40/month maybe more for a service that lets me do it.
It could be free for one e-mail address, $29/month for up to 50, and so on and so on.
This way, the indie bloggers out there who can't sell an ad to save their lives but who get bombarded with PR pitches in their inbox all day can automate their sales process a bit AND get the satisfaction of annoying the crap out of the PR people bugging them.