One of my tried and true recipes for procrastination involves playing with my Amazon wishlist--which, I noted yesterday with a combination of bafflement, bemusement, and resignation, now numbers over 400 items. (I decided it would be more fun to hunt down new Oxford and Cambridge books on the nineteenth century instead of reading Historiographic Metafiction in Modern American and Canadian Literature.) As it so happens, I don't expect anyone to actually buy something for me from the list; instead, I use it as a repository for identifying books I ought to read, books I don't really want to read but should know about, and books I desperately want to read but can't afford to own. In addition, I use it--along with AddAll--to double-check prices before bidding on academic books at EBay.* I'm still irritated by Amazon's decision to eliminate the list-view option for used books, but at least they went back to identifying the used prices in the full wishlist itself.
The wishlist approach replaced my earlier habit of maintaining "interesting books" lists in Word documents, a practice which saved space (because I could then throw out the catalogs) but became too time-consuming. I started keeping lists of books while I was a graduate student--I'm a pretty inveterate lister of all sorts of things, I've got to say--and still riffle through my older lists whenever I start working on a new project.
*--Which is worth doing, because there's no point in getting caught up in a bidding war if the book can be found more cheaply elsewhere. When I bid on antiquarian books, I first look up the going rate on AddAll and then keep my maximum bid well below that price.