Goinggear also has itp lights of all varieties including stainless steel (good for keychain and looks nicer), several colors of aluminum, and even a titanium one. They have 10% off coupon and also free shipping if you order 50 bucks worth of stuff. (like if you got your dad and your dad in law or mom or whatever one too).
I highly recommend loading it up with a L92 Ultimate Lithium battery. You get a slight brightness bump due to higher voltage and it doesnt fall off so fast.
Also, unlike alkaline it will not leak. It works in cold weather, and is better at higher drain applications, and has more runtime.
They are fairly common at electronics stores and house supply shops(home despot, etc) and are reasonably cheap.