I just copy and paste an email from the quantum-foundations mailing list.
Dear fellow researchers:
We hope you can all join us in building a new web-based research community for quantum computing, information and foundations on StackExchange, and possibly earn some social media reputation points while they're at it (good for bragging rights, at least).
StackExchange is a collection of web sites where users can ask questions of a technical nature and receive high-quality answers from their communities. We hope to use StackExchange to coordinate expertise and facilitate research in the quantum information and quantum foundations communities, and so we have created a proposal for a new site dedicated to doing just that. StackExchange has already been found to be highly useful in pure mathematics , theoretical computer science , and applied  and theoretical physics , but our proposal addresses that quantum information and foundations lie frustratingly between these fields, and thus each of these existing sites excludes many excellent contributors.
If you're new to the idea of a StackExchange site, here's some examples of StackExchange sites being used in practice to help make it more clear what we're trying to build up:
stackexchange.com/questions/ 6085/shors-factoring- algorithm-help
(Peter Shor himself answered this one!)
stackexchange.com/questions/ 990/can-we-quantify-the- degree-of-quantumness-in-a- quantum-algorithm
stackexchange.com/questions/ 3777/informational-capacity- of-qubits-and-photons
(Shor answered this one, too.)
stackexchange.com/questions/ 15482/how-do-i-calculate-the- position-on-the-bloch-sphere- of-a-quantum-gate-with-a-giv
(even fairly basic questions are OK)
stackexchange.com/questions/ 11702/how-could-a-particle-be- isolated-to-avoid-decoherence
stackexchange.com/questions/ 370/rigorous-security-proof- for-wiesners-quantum-money
(Asked by Scott Aaronson and answered by Daniel Gottesman.)
stackexchange.com/questions/ 93/models-of-neutrinos- consistent-with-operas-results
If you are interested in helping make this proposal happen, you can help by submitting example questions to the proposal site , and later joining in the private beta once it goes live. Remember, the more people that join in, the more useful the site will become! Currently, we need 15 new users for the proposal to go live, so your help is definitely appreciated. Thanks for reading! We hope to see you on StackExchange soon!
 http://mathoverflow.net/ (
Not actually an SE site, but very similar!)
stackexchange.com/proposals/ 36039/quantum-information-and- foundations