How Can I Help?

Other than answering HN/reddit forum questions, is there a site that I can help startups without having to become part of an accelerator/etc? My juices/excitement flows when I'm helping but I'd like to do this for fun, not a job.

Specifically, a site that goes beyond submitted questions on a forum, something of a formal process with delegated advisors based on expertise (my time is precious and my expertise specific, I can't filter 1000 questions for the 10 I can help on).

Thank you for any information!