Recently, I bought a large LEGO collection in which, during the sorting, I found some pieces I'm completely unable to identify. Moreover, seeing some of them I doubt if they are LEGO at all (could be parts of an assembly though).
Here is a photo of the unidentified pieces:
I hope you can recognize them, please let me know if more photos would be necessary.
Higher resolution photos of #2 with the cup for scale (I really doubt it is a LEGO item but it might be a part of a motor or something):