Hello, fellow Chicagoan! You are correct re: the 2.5" limit for the city. I carry a 2.5" folder ( CRKT Mt. Shasta ) clipped to my pocket. I'd venture to guess that many (most?) officers wouldn't know the 2.5" rule or be concerned about the size of your knife if you're not flashing it about or doing anything illegal with it, whether it's been "concealed" or not. Those of us who carry Leathermans may all be breaking the law, as I believe all but my Micras and Squirt have 3"+ blades. You can't predict the behavior of a given Chicago cop or a local judge, but you should be fine in 99% of situations if you're over by a half inch or an inch. Might avoid carrying an "illegal" knife into a government building but otherwise it shouldn't be an issue. I think I've found a good compromise--my folder is perfectly legal and my Leatherman's a "tool". When I travel, I carry a bit larger sometimes, but the 2.5" blade's fine for most things anyway. BOBs have fixed-blades but EDC doesn't need to be enormous, in my opinion.