Smokey recently produced a function to automatically convert @-mentions to clickable links for micro.blog users.
His regex pattern is simple and works.
He takes a different approach to my hashtag linking function in that his is applied pre save thus changing the actual post content, whereas mine only impacts the output when viewed.
It's crazy how performing the same action at two different times (save vs display) requires such a difference in complexity of solution.
Note: his pattern doesn't work at display time.
I'm sticking to my method as I've only ever wanted the hashtags to be a feature when viewing the blog itself rather than when distributed via RSS, but it's been a good lesson.