Just charge it
The most obvious issue with taking gadgets on the road is keeping them all running. This means power, and that means packing a wealth of AC adapters in amongst your work shirts and duty free. Fortunately, AC adapters are usually relatively small and somewhat self-contained (once you wrap the wire around the adapter), but put five or six of them in your suitcase or carry-on and you're going to notice them.
Sadly, there is little you can do when it comes to those adapters; many are designed specifically for your devices, outputting specific voltages that make them difficult to swap or replace.
A small USB hub is an invaluable assistant: plug all your device cables into the hub, then you only have one plug to remove from your notebook's USB port when you hit the road again.
However, not all products are so fussy. Many devices still run on standard-multiple voltages (1.5V, 3V, 4.5V, 6V, 7.5V, 9V, 10.5V or 12V), which can easily be accommodated using readily available multi-voltage adapters with interchangeable tips. These multi-voltage adapters may run off of AC voltage, or come in versions that can be powered from 12V car cigarette lighters - only useful if you're renting a car while you're away. Cars will definitely also be useful for charging mobile phones, which usually come with car chargers.
Many devices have increasingly moved towards charging from 5V sources such as the USB ports built into every desktop and notebook PC. This makes life very easy for users of portable music players, which typically now use the same cable to synchronise their data and charge themselves. In the case of iPods and other devices with proprietary cables, you'll still need to lug that cable - but many phones, PDAs and music players will sync and charge using a standard USB cable.
By doing an inventory of your devices - and considering which can be charged from your computer using USB - you may find that you don't need to lug so many power supplies after all. One downside to this approach, however, is that you will only be able to charge one device at a time.
You can charge more than one USB device at a time by bringing additional USB cables, but add too many and the USB bus will quickly run out of power and cause other devices to malfunction. A powered USB hub is one way to resolve this issue, but that of course involves carrying yet another AC adapter! Also be aware that charging devices from your notebook battery will run it down much faster than normal operation - so only use this approach when the notebook is plugged into the mains outlet, or when you really, really need that device charged immediately.
On a related note, one of the biggest problems with taking so many chargers with you is the sheer mess of the situation; get your cables stuck together and you're going to lose a ridiculous amount of time untangling them when you arrive.
The solution is simple: use twist ties (or plant ties) to bundle up the cords, and keep them that way when they're plugged in on the other end. To make life easier, you can also buy plastic tags for labelling each cord so you can tell them apart when plugging and unplugging - or make your own labels, as I did, using an inexpensive label maker.