There are a lot of groups on flickr based around type of photography, camera brand, or lenses. I don't post my photos to flickr, but I do read through the forums. There are some pretty knowledgable folks who post there, and even more post photos in their streams.
Another message board is dgrin.com, associated with smugmug.com.
Another message board is dgrin.com, associated with smugmug.com.
But really, I don't generally know how to even begin to navigate Flickr to find inspiration so I stick to what goes on here.