Here's a few more thoughts from reading When Money Dies (UPDATE 5/20/10: sorry, online text has been removed by publisher's request, and it is quite pricey on Amazon).
There were some who prospered during the collapses of currency in Austria, Hungary, and Germany following WWI. There are also areas of need that were particularly hard hit, which caused much suffering in these countries. If you truly believe hyperinflation is about to happen in America, here are some preparations you can make, and some hot career moves.
When currency collapses in value, it is mainly consumable goods that will be scarce. Everybody will be hoarding them. Durable goods will be in plentiful supply, since people will be trading those for consumables—by which I mean food and fuel. The bomb shelter types will be in good shape for hyperinflation. I'd recommend keeping bags of flour, grains, and canned food, enough to last for a year, until the new currency is well established.
In case you forgot anything, have plenty of cigars and cigarettes on hand. In war, prisons, and hyperinflation, tobacco has always served as makeshift money when there is no other. Being durable, portable, divisible, and having intrinsic value—it fulfills pretty well the criteria for natural currency. Bummer about the huge tobacco tax—come to think of it, does the government know something we don't?
Farmers did okay during the Weimar collapse, mainly though the trade of durable goods for food. Either make friends with a farmer, or learn to become one. At least that way you won't starve. At the very least take up gardening if you anticipate hyperinflation. In Austria, in the early 20's, a farmer could trade a few bags of apples for a piano.
Which brings up hot careers: aside from farming, look into finances or the black market. Crazy profits are to be made there. While many starved and died of disease and exposure, others partied—and you want to be one of those. Wall Street types did well during the collapse of the Krone and the Mark, for the exact same reason they've done well in the past decade. When cash is devaluing, the stock market is hot. Foreign currency and stocks were the primary ways people preserved what wealth they had. Since financiers get a cut of these transactions, they will profit handsomely during the collapse of the dollar. They may be losing their jobs now, but they shouldn't get too cozy at their parent's house. They will be plenty busy when hyperinflation hits.
Now, when people are freezing and starving, they will gladly trade their most prized and valuable belongings for food and fuel. While the government tries and fails to ration everything, the international black market will be sizzling. Don't miss out!
If you follow these simple rules and quickly get your money into stocks and gold, there is plenty of fun to be had with hyperinflation. Any schadenfreude renters may now be feeling will pale in comparison to those prepared for the dollar's collapse. At the very least, it will be your chance to loose those 20 pounds you've been meaning to shed.