Re: Help a new member
Please, which ever light(s) you are thinking about, please see the Review thread and check out Roy's, and others, runtime charts.
The X5T's and other non-regulated lights, IMHO, have been exceeded now by the many LED lights available with regulators. An X5T will only last you 5 hours or so before its output drops by 1/2. And while CR123 Lithium batteries are only a $1 or so in the US, other parts of the world may not be so blessed (I guess your "wild blue yonder" is referring to flying to other countries? So, choosing standard battery sizes/types will be helpful (and you won't have the risk of having your spare lithium batteries confiscated).
A small AA or AAA light (CMG Infinity or ARC AA/AAA, Dorcey, etc.) type light is great for the pocket, lasts a long time with reasonable brightness, and spare batteries are easy to carry (I carry a couple AAA spare batteries in my wallet for my Arc AAA).
If you are in need of just enough light--the UK eLED 4AA Luxon 1 watt (under-driven?) is a good one to get (and purchase a holster if you would like to EDC it). Currently on sale at BrightGuy for $20. Reasonably bright spot with side spill, rugged, regulated dead flat output for 11-12+ hours, black or yellow body, and it isn't the end of the world if you loose it. It is even rated for hazardous locations.
The other high-tech lights, like ARC, and others, are great lights--But I think everyone needs a few of these new generation, regulated, and inexpensive lights around their home, work, and play. They won't light up the world, but they will light up your little piece of it.
-Bill