Anything the size of the Spyderco Military or larger becomes uncomfortable when I sit, so doesn't get carried much. I'm 5'-11" to complete the relevance picture.
Stuff in the range of AFCK 800 and BM 710 are fine to carry and sit in a chair with, in my front jeans pocket routinely
I carry from 3" to 4" daily.
In jeans, 3-1/2" to 4".
In khaki's or dress pants, from 3" to 3-1/2" mostly because I don't always clip to pocket for discretion and longevity of slacks.
For dress with sport or suit coat, a small folder and/or a Bud Nealy MCS Pesh Kabz is the deal. No doubt. An upside-down-suspended Kesh Kabz, etc, inside coat pocket is very discrete, very accessible, and just such a fine, truly comfortable and concealable design on Bud's part. Kudos to Bud.
Along this line, I'll soon own an RJ Martin Kozuka which allows similar carry.
By the way, for ordinary/utility tasks, there isn't much reason for anything past 3-1/2" IMO. Since legal limits, God forbid I should have to defend myself, are at 4" in my state, that is my max carry. YMMV. So might your tolerance for large/illegal blades. I also have a concealed carry permit.
[This message has been edited by rdangerer (edited 02-13-2001).]