Sticky/Resinous hops

I am sure that there are other people out there that have had a great IPA, Double or Triple IPA, or perhaps even a hoppy barley wine that have experienced "sticky or resinous" hops. I am talking about the types that leave that sticky residue on the side of the glass and are pungent enough that you are tasting them before the beer even hits your tongue.

So here is the question:

Can anyone enlighten me as to what compound in the hops is causing this (I am currently reading Ray Daniels Designing Great Beers and have some hypothesis' based on his information of hop oils) but I would love to be validated by someone who is more experienced and learned than I am in the use of different varieties of hops. Also are there any suggestions on which varieties would yield this quality and when in the brewing process would be most beneficial to achieve said quality (ie boil time, late addition, dry hop, etc).

Thanks for your time!