If you’re looking for a basic, no-frills PIM app, you might want to check out EssentialPIM. It looks kind of like a stripped-down Outlook. If you want the PIM features of Outlook in a Windows program without Outlook’s email and general bloat, you might like this.

Personally, I didn’t find it compelling enough to switch to. I tend to keep my calendar in Yahoo! Calendar, because it can be accessed anywhere that I have a Web connection and my calendar is easily shared so that (in theory) people can see if I’m available before scheduling a meeting. My tasks tend to be kept in a combination of @action email folders and a TWiki page that holds my status and becomes my status report that I send to my manager at the end of each week.