The ones you can lend to your friends after having read them. The ones that your parents have read, kept and that you took in their bookshelf when you were a kid.

The ones that your friends gave back to you and that will wait in your bookshelf for your children to take and read. The ones their friends will borrow and that will probably giggle a bit, because they will have difficulties deciphering the notes your father wrote on a margin.

Because if content has a price, knowledge ought to be free.

Ebooks have huge advantages compared to physical books. They're availble everywhere (no need for long errands/waiting just to find the book you seek), much cheaper, searchable and don't take up space in your home. They're not lendable (yet), but that's the only issue with them.

I'm not saying that ebooks are "the correct choice". A lot of people still love the feeling of physical books, perhaps rightly so. But please don't tell me that buying ebooks are somehow wrong or any lesser than buying physical books.

- Ecological advantages. Am I crazy or does it seem many pro-environment types are pro-dead-tree? Nostalgia is a factor, but I think vinyl vs. mp3 would be a better analogy in that the proponents can point to certain experiential benefits (tactile, smell of an old book etc).

- Ergonomically more practical in most cases. Weight, page flipping, etc. Downside is eye strain in low light, but the current kindle is not too far off from reading a printed page.

Pirate them. Then they are lendable.