I usually have 2 knives on me if I'm not at work (I voted for the "2" option in the poll): A Spyder Edge Manbug on my keychain for "convenience cutting" tasks and a small or mid-size folder—usually something in the 2.75" to 3" blade range like a Native 5, Delica 4, UKPK, Yojimbo 2, Introvert, Karahawk, Chaparral, etc.—for when a little extra reach and cutting length is needed. Depending on what I need to do on a particular day, however, sometimes I will replace the mid-size folder with a compact fixed blade like the Enuff or Ronin 2 or one of my small non-Spyderco fixed-blades.
When I need to go ultra-minimalist such as when trail running, I carry one knife clipped IWB, almost always a Dragonfly 2 of some sort, or occasionally a Li'l Native.
At work, I carry three knives: the aforementioned Manbug (my most carried knife, now that I think about it, since I always have my keys with me), a 3" work knife (a Native 5 LW, Delica 4, Salt 2, Alcyone, or Tasman Salt 2), and the knife on my Leatherman Wave or Skeletool. I carry a Leatherman mostly for the pliers, wirecutters and screwdriver—I only ever use the multi-tool knife if I'm, say, cutting something against concrete or steel and don't want to risk chipping my Spyderco