In my opinion if you want to have the battery in laptop, make sure it will get charged only when the charge drops below a certain amount. I have it set to 50% in my Thinkpad so the battery only charges after it drops below 50%. Use the battery occasionally so that it drops below the charging point (but never empty it completely) and then recharge it fully.
Or yes, keep it partially charged outside (probably not necessarily the freezer, but it should be a cool place).

if you have one of those older laptops that will constantly charge the battery, take it out and leave it out until you use it... downside is, if you have a power blip or kick the cord out, then your laptop just powers off immediately

Li-Ion batteries store best at full charge... I'm not sure about the freezer thing, so you should look up on it
NiCad batteries store best at no/low charge

ultimately, for any battery, heat kills it... so if you have a cooler fan, you can use it to keep the battery cool too

I was always told if you don't have a battery conditioner that you should always fully discharge then fully charge the battery every so often to keep it from developing a "memory" where it establishes a lower than normal charge threshold as "full" when it could potentially store more energy.

Old NiCd type batteries had memory effect. The newer NiMh had it greatly reduced and Li-whatever generally do not have it.

There are 3 things that hurt current Li-whatever batteries:
- overcharging it (the charger stops charging when it detects that cells burst, so effectively every full charge damages the battery a little)
- undercharging it (the firmware of the battery will actually prevent you from fully discharging the battery...but if you empty it and leave it on the shelf, the self discharge can empty the cells and they won't reactivate anymore)
- heat (over 30°C)

Memeory effect isn't really a problem in any sort of equipment most people will be using.

http://www.dansdata.com/gz011.htm