I know you have to pay for it but OS X is really the most comprehensive planning utility available. Between Mail and Calendar you can create all sorts of events and ToDos and they all automatically sync together including synchronization with your iPod and related devices so your contact list and such is always with you. Both programs are quite customizable and if you make an event in Calendar you can add a list of contacts which will automatically be mailed an invitation through Mail. It's all really easy.
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I know you have to pay for it but OS X is really the most comprehensive planning utility available. Between Mail and Calendar you can create all sorts of events and ToDos and they all automatically sync together including synchronization with your iPod and related devices so your contact list and such is always with you. Both programs are quite customizable and if you make an event in Calendar you can add a list of contacts which will automatically be mailed an invitation through Mail. It's all really easy.