Catching up with Calibre

in late 2006 I took two weeks of vacation around a week long conference. For that trip I had over 50 pounds of books packed (according to the airport scales), the books took up as much room in my luggage as my clothes. since then I've got the Kindle DX (large screen) and my luggage is slightly lighter (fewer books, more electronics) but my available selection on hand to read is _much_ better.

that said, paper books still have their place, and they are still accumulating around the house, just not quite as quickly

since you mentioned Science Fiction, take a look at webscription.net. this is the bookstore for Baen Books, and all the books are DRM free, in multiple formats, and priced fairly well ($6 for the e-book version, available usually two weeks prior to the hardcover hitting the bookstores). they even have a substantial pool of books for free (early books in a series in large part, but not exclusively)