Suggestion: @User - user mentions

@Keleth , I suggest user mention feature.
What it does : It sends PM to that user containing post text and url to context.

Where it useful: When you try to summon someone's attention to post/thread (calling @Cthulhu, anyone?)
When answering someone's post. Add "Reply" button next to "Quote" - It will create new post starting from "@[Username], ..."
I think it useful in conversations if you don't want to extend your post with quotes. And seeing this in your pm will encourage fast back and forth dialog.

Special uses: "@everyone" - sends pm to everyone in thread/game. For important announcements. But it can get annoying.

And I think some kind of setting to control who/from where users can mention you can be needed.
So, what do you think @everyone ?

This suggestion has been brought up before and is on my to-do list. In the currently planned implementation, it won't send a PM, but there will be a different page (Notifications) where you can see any place you've been pinged (I will end up adding game pings later, as well as other types of notifications). In addition, I'm thinking of adding a different new post icon for posts you've been pinged in and a search page like Latest Posts where you can see posts you've been pinged in.

Perhaps have a little symbol on the header that indicates that you have an unviewed Ping?

Yup, that's planned! Right now, you get a small envelope at the bottom right corner of your avatar when you have mail, I'm thinking an exclamation or @ at the top right?