At RHED Pixel, we use the Mac’s built-in calendar and address book to keep the office organizer. Technically, this is a no-no as they’re not really designed for 20 different devices to be syncing at once. But hey... we’re risk takers. I did find two great apps on the new Mac App store today (they are also on the web too).
Here are the official descriptions:
If you're like us, your calendar is how you manage your life. And that means that bad data can mean a really bad day—or worse. Calendar Cleaner removes duplicates, finds subtle problems with your events, and keeps everything clean as a whistle.
Your contacts are the center of your personal social network, and as such are often synchronized among your Mac, your iPhone, and many other apps, services, and devices. Contacts Cleaner finds and fixes the little problems that can creep in while you're not looking.