Here's one thing I've discovered in my many trips to Blargistan: Pack or purchase a small empty duffel, because you will be coming home with books.
Over the past decade and a half, I have schlepped home over fifty pounds of books: four reference volumes (hardcover), about ten three-inch thick exhaustive studies (paperback, but still big and heavy), and more gifts from other scholars than I can count, some of which have absolutely nothing to do with what I work on, but it's the done thing.
What these all have in common is that they're impossible to get in the states. "Someday I may need this," I tell myself. So I pack them up, and sometimes pay an extra weight fee once I get to the airport. I hit upon the small duffel idea several years back, as a way to take the books on the plane and thus avoid the fee. Still, they're heavy, and cumbersome, and every time I'm sitting there the night before my return to the states, wondering how many clothes I can jettison to make room, wishing fervently for a book mule, I wonder whether it's worth it.
Today, it paid off. As part of the chapter I'm working on, I need some background on a particular government official. He was a big deal in his decade-long tenure, but I searched every catalog I could find, in vain, for some article or book about him. Zippo.
Then, I turned to my own bookshelves. I pulled down several of those exhaustive studies that I have yet to crack (seriously -- one of them runs to four volumes, and over 3,000 pages). I flipped to the indices. And lo and behold: four of the books I hauled home over the years have extensive entries on this guy.
So I've got the books stacked up on my coffee table, ready to dig into tomorrow to find out whether the text lives up to the promise of the index. I'm relieved to have something -- anything -- on this guy, because it looked like I was hitting a dead end that I could not afford to hit. I'm tickled pink that they were right there all along. But I'm also just as pleased that all that book hauling has paid off.
 You can actually view about 80% of these in the "after" picture of the previous post: they're the two middle shelves on the center bookshelf. The remaining 20% are up at my office.