jasiek You can control the session per user in: Menu -> My Settings -> Control Panel -> Misc (miscellaneous): Keep session at least: the max you can select is 8 hours.
littlebearz tweak the CommonDataCommon_0.php or search for $_SESSION. I remember tweaking it and it won't expire for 2 weeks on my cellphone. You still needs the cookie to be there in order not to expire.
