Where do you keep any books borrowed from friends or the library? Do they live with your own collection, or do you keep them separate? Do you monitor them in anyway.
I don't put my borrowed books with my own book collection because if I did, they would never get back to the proper owner. I normally keep library books and books from friends on top of my piano. The piano is right inside my front door, so this is an obvious place for me to use. This way, I can see my borrowed books before leaving the house, just in case I need to return them.
I try very hard not to borrow books from friends, mainly because I don't like to lend out my books. After you have had a few books go missing because you have lent them out, you learn to be more possessive of your books. However, I do check books out of the library on a weekly basis - for research, book reviews and pleasure reading. Having them within eye sight keeps me on track with my reading and reminds me I'm on a deadline to finish books and return them in a 2-week period.