My Pelican is rated at 60 lumens output for 1.25 hours. Most of the others are similar. Some of the Surefires have an optional hi-output lamp assembly good for about 20 minutes. I don't think this is worth it though - 20 minutes is rarely enough, and if the batteries aren't fresh, you only expect them to last, on average, maybe 10 minutes. If you really *need* the brighter light, go with one of the larger 4- or 6- battery Surefires, which runs brighter for the full hour.

But an hour is good enough for most emergencies. If you know you're going to need light for longer (if you're a security guard, police office or participating in a search-and-rescue operation, or in an extended blackout, for example) you need something bigger, or preferably, rechargable (to defray the cost of going through batteries like candy). One of the longer Mags will last about 12-16 hours per set of 'D' batteries, and makes a pretty good club - actually IMHO it is better as a club than it is a flashlight. The Streamlight Stinger is intermediate in size, and rechargable.

If you use CR123A batteries, buy them in bulk online (usually they come in packs of 12 for about US$15-20). In a pinch you can pick up a pair at a store (ask for "digital camera batteries"), but you can expect to pay about US$4-5 for *each* battery.

In my estimation, I get more than 1.25 hours total because I usually only use it for short bursts with relatively long "off" periods in between, so the battery is used somewhat more efficiently (when it runs continuously, the Ah rating is somewhat lower). Unfortunately, unlike alkaline batteries, they tend to die all of a sudden, so all you get is a few minutes' warning of diminished output, and then darkness. So I carry a spare set of batteries in a jacket pocket, so that's always available.

Add to that a small MiniMag or similar 2-AA or LED pocket light, or even a keychain light, which can be pressed into service if the main light fails, and also can be used so you can see while replacing the batteries in the main light. For something as important as light, one is none, and two is one.

You could even kick in a cyalume glowstick if you've got the carry space - these are useful if there are suspicions of flammable gas - don't want any electrical switches being actuated in an instance like that.

As far as bulbs go, I purchased a spare bulb when I got the light (for an extra $6 or so), but I haven't yet had to replace the bulb after almost a year of light-duty work. It's not like my old MiniMag, where I'd need a new bulb after every second or third set of batteries.

Surefire now has some lights which include both an incandescent lamp and LEDs arranged around the bezel, with options for "low" (LED), or "high" (incandescent) settings.

But I prefer to have two physically separate lights in separate pockets, with spare batteries in another pocket still - the redundancy is total in case one gets lost, and the price is cheaper. In particular, you can use the light of one to change the batteries or the bulb, or to find the other if you drop it.