Currently two, I have a preon p0 on my keychain and a preon p2 ill pop in my pocket if im going out and I know ill be out past sundown.
i carry a streamlight nano on the keys, icon Irix (headlamp from woot...very cheap) in my work bag, huge mag under the seat in my truck, so three as well.
While at work I carry four. Fenix LD40, Streamlight Microstream stylus, Streamlight headlamp in toolbag and Photon LED on my keychain. While out and about a Fenix PD20 and the keychain light.
Fenix LD10 - Left front pocket LumaPower Incendio V3 XM-l - EDC Bag (MOAB 10) Streamlight Microstream 1xAAA - EDC Bag/Left front pocket if the LD10 is not there Battery Junction keychain light - EDC Bag CountyComm SO-LED - Cliped on outside of EDC bag MOLLE strap So..... short answer is at least one on me at all times and several others in my EDC bag and/or vehicles.
I usually carry one (And call it "is none"). Formerly, it was a brass peak Eiger on my keychain; lately, it's an AAA IlluminaTi in a Mission wallet.
Three always on me, a preon 2, Zebra Light SC600, and a photon on my keys. In the bag there's a Fenix TK-41 and a surefire E2D. In the car is another TK-41, surefire E1b, and a few cheap headlamps.
Used to be two, my L1T and a TK10. The TK10 has since been returned to it's rightful owner. Now, it's usually just the one (L1T, ZebraLight H502, or a Jetbeam PA10). Wanted to change that, so I figured I'd get some tiny stash-away lights that I can just throw into bags/clothes and forget about. Which is why, this
when I try linking a pic from my flickr it ends up making the text after a link to the picture.... I just want it to be plain text.