Much to my irritation (and that of others), many hotels charge for broadband internet access and the standard practice (at least on this trip) seems to be to charge per computer. So if both you and your traveling companion want to connect to the internet (via ethernet cable one at a time or both via wireless), you’re screwed. Luckily, we brought along an Airport Express; it’s small and fits easily in a suitcase. You hook that up to the ethernet cable and then you can both connect to that wireless network.
(With the Powerbook, you can also hook it up to the ethernet cable and then share your connection via the Airport. But the cables are typically short, so one of you loses that lounging-in-bed web surfing experience.)