The credit crunch might be doing nasty things to your job prospects, but it has one potential upside for travellers: hotel room prices are falling across the globe. However, last-minute discount deals won't always represent the best value.It doesn't take an economic genius to work out that when people are reluctant to spend money, hotels will have to respond by dropping their prices. This has been very evident in the hotel prices being offered in Las Vegas for the annual Consumer Electronics Show which takes place in Vegas. In previous years, it hasn't been uncommon for hotels to quadruple their prices for the week in January when the show takes place. However, as I write this, the official CES site lists several examples of hotels which have reduces their rates multiple times in recent months. There's also broader statistical evidence of a drop in prices. The Hotel Price Index maintained by Hotels.com found that average global room prices fell by 3% in the July-September period, the first time the site has seen any price fall since it began tracking that data back in 2004. That average also conceals some much bigger falls: Vegas, unsurprisingly, has dropped by 20%. While you might think that means the weary traveller can look forward to some savings and that it's time to snaffle a last-minute bargain, the truth is more complex. For one thing, city pricing is still highly variable, and Australia doesn't seem to be seeing the same discounts. Melbourne prices, for instance, actually rose by 24% in the period, and Sydney prices were static, Hotels.com found. In Europe, overall prices were up by 2%. When it comes to overseas travel, exchange rates also play an important role. In this context, minor price falls have generally been balanced out by the declining purchasing power of the Aussie dollar in markets such as the US. A room might look cheap now compared to six months ago, but the total cost won't necessarily be very different. My own recent experience bears this out. Back in July, I booked my own CES hotel room at the Imperial Palace for an average rate of around $136 a night (Australian dollars). Right now, the Imperial Palace is offering a rate of $US700 for the same room on the same dates, which is actually lower than the original price I was quoted. However, that $US700 translates into almost exactly the same per-room rate once you convert the currency -- and this in a market which has experienced steeper room price declines than almost any other. If I'd made a booking in New York or San Francisco, I'd certainly be worse off. If you can find a good hotel deal and squeeze in an unexpected holiday, that's great. But for trips you know you need to schedule overseas, booking and paying in advance still offers a degree of price certainty that's hard to match, so I suspect I'll still be sticking with that model. Lifehacker Australia editor Angus Kidman spends a lot of time in hotels, but tries not to spend a lot of money in them. His Road Worrier column, looking at technology and organising tips for travellers, appears each week on Lifehacker.