I'm really liking the SK7's one mode @ 35 lumens. A very nice balance of runtime and output that goes good on my keychain. SK3 isn't a slouch either. Check out the flashlights below. Unfortunately the only 10440 I used to have to my LD01 doesn't work anymore so I can't test the SK7 on 10440 myself.
Spark SK3 1xCR123/RCR123 XPE Flashlight
Spark SK7 1xAAA/10440 XPE Flashlight