Today I ran across another fine StackExchange site, security.stackexchange.com, that I had never visited before. The question I viewed was interesting, and the most highly voted answer was insightful; but the answer also contained a false statement. I was, sadly, unable to comment on the answer and help improve it, because I lacked the necessary reputation on security.stackexchange.com.
This isn't the first time I've wanted to comment, but was unable. I often find myself wanting to add a small note to someone's answer, or request clarification from the author on a site I've never visited before. New StackExchange shards seem to pop up with regularity.
So my suggestion is this: Let a user's reputation on a given StackExchange site carry some (lesser) amount of weight with other related StackExchange sites.
Shouldn't my rep on StackOverflow carry some weight with SuperUser, programmers.stackexchange.com, or other related sites?