[DragonByte Tech]

@ctrlbrk: I understand your concern, the reason why we didn't implement AJAX checking like FaBook does is that not only may it be hard (or impossible) to hook into the WYSIWYG editor (that's yet to be confirmed, we'll investigate for the future though), but it may cause confusion if an user is typing an email address and not attempting to tag.

Additionally, the AJAX check isn't instant, so users may put typos in there before the AJAX check has a chance to kick in.

It's certainly something we'll look into though, I'll raise this as a Task in our project tools