Automatically link posters to their user profiles?

I’ve got about 5 or 6 people who post on my blog, and it will probably wind up being eventually 10 or 11. I’m trying to make it so that when they post, their name is linked to their profile. Has anyone been able to do this? I’ve been through the forums pretty thoroughly and haven’t seen this as much of an issue – I would have thought that this would have been a pretty standard feature. Or, maybe I’m just missing something obvious (which is the more likely explanation).