However I have a Florida Concealed Weapons Permit which allows me to carry a variety of "weapons" concealed.
790.06 License to carry concealed weapon or firearm.—
(1) The Department of Agriculture and Consumer Services is authorized to issue licenses to carry concealed weapons or concealed firearms to persons qualified as provided in this section. Each such license must bear a color photograph of the licensee.
For the purposes of this section, concealed weapons or concealed firearms are defined as a handgun, electronic weapon or device, tear gas gun, knife, or billie, but the term does not include a machine gun as defined in s. 790.001(9). ..emphasis addedhttp://www.flsenate.gov/Laws/Statutes/2010/790.06 I don't consider a knife to be a weapon. To me it is a tool. I normally carry a fully serrated Spyderco Endura with a 4" blade for tougher jobs in a pocket of my cargo pants and a fixed blade knife for tasks such as food prep.
Spyderco Endura I carry the fixed blade knife openly in the small rural town of Florida where I live and it attracts no attention. However if I journey to a more urban area such as Tampa I carry a neck knife under my shirt. Florida police have little understanding of the knife law and I prefer not to attract negative attention from either the city cops or the citizens who are unfamiliar with the open carry of a fixed blade knife.
One fixed blade that I often carry is a BRKT Classic Lite Hunter with a 4" blade

My neck knife is a BRKT Bravo Necker II, the larger of the two knifes in the picture. It has a 3.5" blade.

As I said, I view a knife as a tool. For a self defense weapon, I carry a S&W Model 642 .38 in a pocket holster.

Switch blades are interesting knives and not illegal to carry in Florida. I own one but I never carry it as I see no real advantages to its design. Knifes and concealed weapons are illegal on school grounds.