It takes 1.3 seconds for an assailent to go from 21 feet to slapping you upside the head. How long will it take you to reach down and draw your carry gun out of an ankle holster? The previous advice of an ankle gu being a back-up to a main carry gun is 100% correct.
When looking for a carry, look for something you WILL carry. So many guys buy big Glocks, Colt's, S&W's....whatever and end up not carrying them because they get to be a PITA!! To big, cumbersome, heavy to carry all the time.
The Kel-Tec and Rugers copy LCP are good little guns in .380...about the minimum a guy should carry.
A couple of guys have said something about them not having safeties....don't let that sway you.....it is a double action only gun and designed that way. No real need for a safety as it requires a long trigger pull to fire. I personally don't see a lot of difference between the Ruger and the Kel-Tec....other than price. Sure the Ruger is a tad better finished but who cares....its a carry gun.
A nice J-frame Smith is another good choice. Can't really go wrong with a revolver. Too many people have problems not maintaining a solid grip on the little pocket guns and then wonder why they jam. A limp wristed/light hold on these little mouse guns allows to much of the reciol to be absorbed and doesn't allow the action to function correctly.
Good luck in whatever you chose.
WW