Hmm, Only 3?
1) A "Kayak-Gun" (Yes, I had to bring this up sooner or later.) It would be mostly parkerized/blue (not a big fan of the nickle guns) but extremely resistant to corosion and salt water. If an auto, it would probably be chambered in 10mm, or wahtever the FN FiveseveN is in. Actually, a 100% corosion and water proof FN FiveseveN would fit the bill nicely. Or maybe base it on a 1911 or revolver so that you can get a wider variety of callibers - a .22, .45, 9mm, 10mm, 44magnum.....
2) another revolution in pocket guns. Either something like the NAA minis, but with a double action trigger and trigger gaurd, or a 5 shot snubby in 327Federal. or 7.62Tokarev. Yea, a five shot, 1.5 inch barreled DAO - it would be (in theory) slimmer than the .38 snubbies, and maybe easier to carry IWB, but still pack a nice punch.
3) I'd say an affordable FAL, but that will never happen. I'll settle for a speedstrip for revolvers thats flexible. You can carry it as easily as the normal speedstrips, but you can bend the two ends together and load all 5-9 rounds (depending on the gun/calliber) at the same time like a normal speed loader.
3.) somehow a double barrel semi auto shotgun that had 2 tubes one under each barrel. That to me would serve so many roles I think it would be a winner all the way around.
I had a dream once: I was hunting vampires (Can't stand what they did to Forks...) and my shotgun was an over/under. underneath the two barrels where two tubes that together would act like a single stack magazine. You'd fire both barrels, but the bottom one functioned like the old berreta "tip up" .22 pistols. capacity of an autoloader, performance of an O/U. Just something to think about.....
Chris "the Kayak-Man" Johnson