[SkyMarshal]

A Stackexchange site might be too. It seems the main difference b/t the two is that the Reddit/HN format is oriented submitting links for discussion and pithy comments, whereas SE is oriented around submitting questions for specific answers and collective problem-solving. The latter might be more what the OP is looking for.

[megamark16]

I prefer the subreddit approach, mostly because I subscribe to the subreddit and see new stuff there in addition to all my other reddits, without having to hit an extra site. Mixergy's community (FoundersMix) is great, but I don't care so much for the StackOverflow engine for general discussion.

[icey]

iirc, they're changing the StackExchange model so that it has to be blessed or approved before you can create one. Additionally, SE isn't really a great platform for fostering discussion as much as it is a platform for Q&A.