Just read through all the comments and wanted address fellow wooters about some fallacies and some truths about batteries.
Please note this is a long (but informative) post
Never use batteries in colder weather, they drain faster, unless you're okay with that. Freezing your batteries does slow self discharge, but it's really not needed as most modern batteries last like 5+ years in storage. Freezing does not refresh batteries, letting them rest after deep drain causes the cells to refresh a bit, not the freezing.
Also freezing your batteries can destroy the seals that keep the electrolyte contained, causing premature leakage.
Once you start using a battery, use it all. Once you start draining a battery the chemicals inside begin to accelerate in their degradation, causing it to lose efficacy as time goes on. This is where the whole freezing your battery practice came from, to try and slow this reaction.
Alkalines do indeed have more energy storage (density) than Zinc batteries. Battery life depends what you're using the battery for. Since Alkalines have more power, they last longer under heavy loads, such as, motors, high intensity lighting (non-LED), and radio equipment. Zinc batteries generally do not last long under such loads as they usually have half or a third the power of Alkalines, but do well in long term small load applications like, wall clocks, smoke alarms, and remote controls.
When looking at batteries you should make note of the amp ratings. Typically "AA" Alkalines run the gamut of ~2000-3000 mAh, and "AA" Zincs at ~500-1500 mAh. What this translates into is an average "AA" Alkaline can produce 2.5 Amps of power for one hour before it's dead, and a Zinc produces 1 Amp of power for one hour before it's dead as well. Though these numbers can fluctuate due to the measuring criteria battery companies use to come to these numbers.
To put this into perspective...
A portable CD player (think DiscMan) that consumes 500 mA of power to run can last ~5 hours on Alkalines, or ~2 hours on Zincs. This could be less, as the batteries are used up, the voltage declines and may fall below the devices needs before the remaining energy in the battery is used.
A LED flashlight would fall nicely into the catergory where a Zinc battery would have a decent usage. A typical LED flashlight (Non-Cree), uses LED's which are either strobed or direct current driven. They usually require 20-50 mA for a single LED implementation. So an AA Alkaline would power said flashlight for ~50-125 hours, and a Zinc for ~20-50 hours. Multi-LED flashlights would naturally decrease these times.
So really, this woot isn't a bad deal, just not a super savings.
On a closing note, using any battery in a deep-drain device and then leaving those batteries in that device for a prolong period after having drained the batteries below 40% is at risk for leakage, as the seals breakdown from the heat produced from the high current drain. This is why you tend to see "exploded" Zinc batteries in old Krypton/Xenon flashlights, as they are rapidly drained and left for dead (this is a non issue with LED).