When designing a system for programming use, and you want to query a large group, is there a better option than just asking Stack Overflow or any other large programming community?
I usually design the main concept of the application, and add/specify the design when I am programming. Design can sometimes be blocked by library usages/etc.
If you work for a company: ask colleague's If you are a freelancer: ask SO/google
I've always found Stack Overflow to be the best place for getting correct and concise answers from programmers. Too many other forums and Wikis get spammed with too many uninformed answers - SO doesn't seem to get that.
Another option might be LinkedIn but I think you'd get more credible answers on here.
No. StackOverflow rules.
But really, can you explain what you mean more? In general, the best option is a mix of input like this and a solid group of individuals who will definitely be either building it or participating have a discussion or meeting about it. Draft specifications, pass them around, revise, then do it all over again.
Wherever programming community you go, there would be bias to one language or another.
For example, programming.reddit.com is a large group but you'll be hearing a lot about how much php sucks and how haskell and lisp are the best.
You could also try going to IRC, but once again, it depends on the community that is currently in the room.
Google serves you better when it comes to resources. But when you are short of ideas, or want a broader view of some concepts and better understanding, stackoverflow rules. I don't think there is another forum as diverse as stackoverflow.
And moreover, you will find less junk here since people wouldn't want their reputation to be hurt :).
Look at these questions for more related stuff:
What are your top developer sites