I usually carry my Buck Special or another fixed blade knife openly on my belt (in Bellevue and Omaha), but I won't take it into places where I think people might freak out (like WAL*MART, even though they sell them), or a bar, or places that don't allow weapons. Surprisingly most people don't look twice at it (or at all) most of the time.
Be aware that in Iowa the knife laws are even sketchier (no blade more than 5" unless hunting or fishing at the time, so no Buck Special...), and in Council Bluffs you can't have a blade more than 2.5" if I recall correctly.
As far as switchblades go, I have a very nice assisted opening knife that I won't carry just because it would probably be considered a switchblade, and cops usually frown on them whether they are legal in your area or not. I see a lot of people carry them though...
Most places in Nebraska though as long as you have a blade that is demonstrably under 3 1/2" (concealed or openly carried) - and keep in mind a judge would likely count the part that isn't sharpened - it isn't even considered a knife by law so go for it.