First up is a field notebook transformer, it can provide various voltages from 12V which is readily available from field sources like Sealed Lead Acid battery. My transformer failed a few months ago and after close inspection, it was found that the fuse inside the original cigarrette lighter plug! To simplify the whole thing, I had removed the plug and installed two alligator clips there so that it can be attached to a Sealed Lead Acid battery directly! Don't worry, there's another fuse somewhere and it won't burn my notebook. However, with these clips in place, the whole setup is simpler and more portable.
Next is a power supply cable for my 1394 hubs. I have a cable made with 9V battery interface, but then the native voltage of 1394 should be 12V instead. So, I bought a cable which has a 2-pin style socket in one end, and I've installed two alligator clips on the other end. Therefore, this cable allows me to connect a Sealed Lead Acid battery to nearly any plug - and I've got so many these kind of plugs from different transformers, for example, to any notebook which is 12V native, to my LXD55, and any other things.
Very neat and convenient.