"The web is great for serendipity and will eventually leave books lagging far behind in that area (it certainly has done this with respect to library stacks). But nothing will ever replace the sense of excitement one can get from antiquarian books if one is a lover of history and traditional learning."

I find the serendipity bandwidth of wandering around a bookstore much higher than the Web. The Web, however, is more more available to me. But wandering around the real world has a lot going for it.