My collection is growing so much, I have a dedicated shelf to them, but even that is over flowing, so I also use Amazon Kindle, I started using it some time back, but although the reading was great, I just could not get on with the references I wanted to make, the highlighting made a list, but it was not easy to get at, and there was no search.
By contrast, with paper books, I often would add a sticky tab, to remind me of something, but even that got out of control.
Then I found Evernote, and life changed, to the point I scan, photo my links direct into Evernote, the OCR is brilliant, to the point of, what would I do without it. I can be reading a kindle book, and see a reference I want to keep, so I take a screen shot and save the photo to Evernote, the OCR will pick up the points I want, but if I want to make it absolutely clear, I can highlight the text this way I can see the text I want, I tag everything, so searching is made easier, I now scan almost all documents, and my reading is now not littered with yellow tags.
All my blogs get posted to Evernote, via the very Wonderfull ifTTT, a free service to watch this blog and for every new post, it posts to evernote.
Even my Moleskin gets the Evernote treatment, my writing needs to improve for the OCR to work, but given enought tags, I can find most things.