I have a Victorinox SAK that has been in my pocket every day for the last 25 years. I think it is the Spartan Model. Three and one-half inches , large blade, small blade, can opener, bottle opener, awl and cork screw. Tip of the can opener and bottle opener are screw drivers.

I carry a larger knife outdoors, but my SAK is always in my pocket. It is small enough that I have never had anyone object if I pulled it out around the office to open a box, clear a printer, or what ever. In the old days, I never had any problems getting on an airplane with it. These days, when I am in an airport and reach into my pocket and it is not there, it sort of feels like I am walking around without being fully dressed.

While mine is ONLY 25 years old, similar models have been around for over 100 years.

If I ever loose my old friend ( it doen't look like I am going to wear it out anytime soon), I might opt for the Tinkerer, same knife with a phillips screwdriver in place of the corkscrew. Of course, the corkscrew has been handy a few times.

So I will add the basic SAK to the list of good stuff before they started improving it. It does not replace a good lock-back or fixed blade when you can carry one. But, it is real handy to carry every day and anywhere, except airports.