bits

I've had to learn the hard way that whenever you're taking a business trip (or a leisure trip for that matter) there are certain essentials that you have to bring with you, such as your towel. While having a laptop with your familiar environment and your favorite tools and music can make your life easier, it's not absolutely essential, given that you probably have an Internet-accessible box at home or at work. What is essential is a quick, straightforward way to get the job done. You need to be able to link your bits with their bits and measures. A simple way to patch your technological know-how into their system. Thanks to Microsoft et al deprecating "legacy" serial and parallel ports, now there isn't any simple, immediate way to interface stuff directly to a PC-class computer. You usually interface stuff directly to a microcontroller-class computer, but even that needs to be PC-linked to be programmed. So even if you're certain that you can find all the needed parts on-site, you still must always bring your own USB AVR programmer.