At least one of my local Costco warehouses (Centreville for you Northern Virginia types) has (had?) 3 packs of 3-AAA LED tactical flashlights for about $17. Nominal rating of 100 lumens on high, and claims 'half brightness' on low, plus a strobe mode, for the flashers. Machined aluminum body, o-rings for water seal, rubberized end cap. NOTE: These are NOT the $100 for 2 set on their website.

I'm not trying to claim that they are as good as the super high quality/ uber bright lights out there, but for a bargain price, they are bright enough to see reasonably well by, and way better than my Walmart/ Target specials (they are significantly brighter than my previous ~brightest~ "bell" multi-LED 4-AAA light), and cheaper, to boot. The cheapest equivalent lights I've seen are 100-110 lumen tacticals @ aforementioned big box retailers for about $13-5 Ea.

I think they'd make great back up lights, if you're already running quality lights as primary, but they seem bright enough (in my opinion -- obviously YMMV) to work as primary for someone with a mostly urban/ MUP commute, and on a budget. I've only used them a couple of times, so no predictions about long term service or such.