A potential thing that should get a sound round of debate for privacy reasons -- there are pros and cons to getting more context for the comment in terms of what it was in reply to (post or comment), many of the cons privacy-based. (On LJ, I've seen spam comments that look like normal comments until you realize that they have nothing to do with the context at all and it's a spam-journal luring you to come back and check out their wares (or warez, whichever), but then that strategy is Not So Good here due to the invite codes.)