eveready makes a 2D incan with one built in. If you have place for one you can find a cheap red LED flashing button or pin and pull the circuit out and use it with a resistor to drop voltage some so it flashes dimmer. I put a flashing LED in my mini fluoro/LED lantern mod and it works great.
There are a few lights with locator flashers but I like glowrings or tritium markers a lot better. Just attach one to your favorite torch through the lanyard hole.
Yep, my vote for the Inova 24/7. Flashes white, white SOS, red and amber flash and the insane white, red amber flash. Check it out on their website.
HDS Ultimate 60 flashes as well: bright flashes and locator flash.
The 24/7's white flashing mode will kill the batteries pretty quickly. Not only is the intensity and duty cycle high, but if you put it to your ear you can hear the dc/dc converter running. The locator mode is activated by setting the switch halfway between two settings. It blinks the red leds dimly, once every several seconds.
Eveready also makes a 2D incan light with a blinking red led, that costs around 9 USD retail around here.
The Energizer 'Find Me' flashlight has a red LED that blinks approximately once every four seconds so you can find it in the dark.
This LED and its flashing circuit is connected in series with the bulb (probably across the switch), so if the bulb is burned out, the LED will not blink.
I like the Eternalights. My Xray and Max have that Nightbeacon feature, a blue led that blinks every two seconds, supposedly for two years. And it floats (with lithiums), and has multiple strobe modes, all that.
Garriey makes a 3-AAA 1-LED flashlight with a green blinking "find me" LED mounted on the side. It has three brightness levels and two flash modes. Unfortunately there's no model number stamped on the unit. I found it for something like $8.00 AT A Wal-Mart.
I dislike green LEDs on flashing or otherwise as they are bright and ruin your nightvision. My roommate has one of those garrity and ends up putting something over the blinky because it keeps him awake by his bedside.