Pop pop pop pop... OK, so I don't really like shooting .22, as years of incicent popping on the 3P ranges kinda wore me out on the round.
However, if someone decides to hand me a little pocket pistol in that caliber, I wouldn't say no.
In terms of versitility, .22 LR can run an entire gamit of usefulness. They're will likely be a new AR-7 around here in the next few months, since a small .22 rifle is useful for everything from eliminating vermin to aquiring small game to SD in a pinch.
Same goes for the pocket pistol. It wouldn't be my first choice for SD, but it can't hurt to have one around.
It doesn't break the bank to feed, either. The only real downside, I'd say, is the fact you can't reload rimfires. But it's cheap, plentyful, and easy to store, so who cares.