Mighty Mouse
For front pocket, any day, any way, pack it and rack it carry, a Kel-Tec P32 is hard to beat. Why? .32 cal, 6.6oz, cost around $200 and forget about it.
A close second, but substantially heavier at 20 oz. is the Bersa 380. Man, for ~$200 you would never expect to get such a sah-mooth shooting little gun. I was just blown away by the out of the box accuracy. It has features that you just don't expect to find on a little gun from Argentina: decocker/safety, combat trigger gaurd, beaver tail grip, a very decent DA/SA trigger, decent sights, finger rest on mag, take down lever, it's just amazing. With the single stack mag and slim body it can hid pretty good as well but you need a big cargo pocket, bag, purse, etc. So maybe not a mouse gun, perhaps a rat.
Waiting to see what the Kel-Tec P-3AT does. It has the potential to be No. 1 with 380, 7.6oz, ~$200, but performance and time will tell.