I use 2 applications.
the first is Dragonfly by MXac Software (
www.mxac.com.au) - this is a "life organizer", with a journal, address book, Calendar, reminders, project organizer, etc. It's a pretty heavy duty app - i've used it about 3 years now and am really happy with it.
The second is Mozilla Sunbird (
http://www.mozilla.org/projects/Calendar/) - i use the stand alone Version, but ther'es also an addon for mozilla (and maybe firefox i'm not totally sure). It's a simple Calendar app with at odo list and a day planner type thing. i use it to track thigns that are time sensitive, as dragonfly's not so good at that.
I've also used timeCalendar LE (no website that i know of), but was unimpressed.