In My Humble Opinion

Google Calendar(s)

This is good, clean fun if you're a geek like me! Sign in to your free Google Account (if you don't have one, just click the "Sign In" link in the upper right corner of any Google page to get started) click on Calendar and you can create, manage AND SHARE your calendar(s) with anyone else who has a Google calendar.

In my case, I have 2 calendars: my day-to-day stuff, and a completely separate calendar for birthdays, anniversaries and recurring events. Why 2? Because I use Outlook, Palm Pilots, Blackberries, and Practice Management Systems (TimeMatters and Amicus Attorney) that ALL synchronize with one another. I have found that they each handle recurring events in different ways, so, I put my recurring stuff in a separate calendar.

Now, in addition to my 2 calendars, my partner Cheryl has 2 calendars: her day-to-day stuff and a separate calendar for keeping track of her parent's medical appointments.

We used to try to keep all this stuff on a big honkin' paper calendar, but it wasn't working for obvious reasons.

Now, we both use Google calendar and we both see (or hide) any of those 4 calendars.

And here's the best part. We each use a Blackberry and Google Sync allows us to view all of those calendars on our Blackberry calendars AND also automatically updates those calendars through the air! So, I can add an appointment to my Blackberry while I work in Huntsville, and if Cheryl happens to be in Toronto, that appointment appears in Cheryl's Blackberry calendar just a few minutes later. No physical connection to a computer necessary!

Google Apps

This has HUGE potential, especially for an organization that has NOT already invested in their own internal infrastructure (servers, network, etc.). This web-based "suite" (?) can eliminate the need for MS Office and even allow sharing calendars without an exchange server!
With only an internet connection, Google Apps users can send and receive email, manage multiple calendars and scheduling, do basic word processing and spreadsheets, and share documents and information with their colleagues. The users don't even need software beyond the Operating System.

Pros
Multiple OS
Multiple hardware
Geography is irrelevant
Cheap
Backup is not needed
Remote access from any internet connected computer, without special software or certificates

Cons
Confidentiality
Lose your Internet connection and you're dead!
Limited word processing: no mail merge, etc.
Still need Powerpoint or similar, database application, etc.

Office 2007

A winner. Relax. The "Ribbon" is great!