Re the mobile phone scenario, this is something I have always said that happens naturally without people being aware of it, hence the reason why mobile phone batteries always seem to get the most life out of them.
Laptop, again something I have always advocated, if possible remove the battery on any laptop/net-book that is used on the mains for most of the time.
My BIOS has the facility called "Battery Management" basically the instructions are to charge the battery to a full capacity then run the battery management option in the BIOS which totally discharges the battery on a very slow and even rate, followed then "by being recharged 100% once the laptop stops doing it's thing".
I usually leave mine discharging over-night as it takes quite some time, then switch the mains power back on the following morning to charge it up again. This process however should not be run too regularly.
(but I'm not sure how often it should be run so I only do it possibly 3 times a year)