A book geek's timewaster, Shelfari helps you organize the books you own and share your preferences with the rest of the readers on the internets. My shelf has mostly travel and photography books, plus a whole section of graphic novels, and this is just the tip of the iceberg.
I have more than a 1,000 and most are hardcover....and since then I've shifted to e-books since I ran out of space. My problem isn't the cataloguing, it's the retrieval. It's one book on top of the other or stuffed in a space available.