These are also good:
http://www.hatch-corp.com/detail.aspx?pid=LMG100/200
Surprisingly, if you can keep the hand warm, the fingers will stay fairly warm without a lot of insulation on the finger.
I keep a pair of just the patrolman weight gloves handy for those days that it's too cold for No Gloves.
Even the "Mechanix" gloves that are available at Auto Parts stores are good and allow for complete movement of the hand/fingers when handling a gun. Probably more available than the Hatch brand.
A tip that works. Take a pair of leather gloves with a fairly thin lining, cut a slit across the trigger finger portion (side to side) approximately half the distance between the first and second knuckle crease (palm side). A quick tug on the finger tip of the glove can free the finger tip to access the trigger and allows the same feel as when not wearing gloves. This works well for precision rifle shooting in the cold too.