Excellent question. Deal Extreme has a bunch of items like http://dx.com/p/1-5v-350-400ma-constant-current-led-driver-board-for-diy-flashlights-128096
which may well be exactly what I want, but the description is so poor I can't tell. "Voltage: 1.5V" do I just assume they mean input voltage and it outputs a higher voltage? Even if so, what is the maximum output voltage, the maximum input current, will an Alkaline AA even be able to power it? Does it have to be 1.5 volts, can I use 2 cells to lower the current needed? It really is frustrating. Maybe I should just order something that looks promising.
I took a look at the datasheet, PAM2803 based modules could be good. Maybe that's what a lot of these modules use, they seem cheap enough. I'm located in Canada.
Yeah, the one you linked ought to work. I have a similar one at home which I did some testing with. http://i203.photobucket.com/albums/aa281/mg_steele/sk68_table_zps002aed83.jpg
This was all done on the bench using a bench power supply and a Cree XR-E. The current draw suggests that this driver wouldn't work too well with a single alkaline cell. Add to that the additional resistance from the switch and the battery contacts of the flashlight, and I would imagine it would still power the LED, but at much lower output current. I would recommend using a single NiMH or Lithium primary cell, or like fungus said, 2 AA alkalines.
In my experience as long as you keep the input voltage slightly lower than the Vf of the LED, you should be fine with just about any of these 1AA boost circuits.