The one I am speaking of is called the SwissMemory. It is only a few cm. long, and has: laser pointer, 2gb USB flash drive, ink pen, scissors, nail file, screwdriver, and yes a small blade (which is excellent for opening mail). To be honest, the blade is the least used of all of the tools on my "knife". This is the one I have with me everywhere, except when flying for obvious reasons.
When hiking or in the woods, I usually have the Victorinox Trailmaster. A bit larger, but just as useful, especially when outside.
As for getting into trouble/starting fights/misc. bad stuff, I have no intention of that sort of thing. It's just not what I do for fun, sorry.
Of the two, the Trailmaster is the one I would have a concern about.