

I am a huge Google fanboy. I wish there was a google photo editor, a google virus protection program, a google toothbrush, a google Japanese course. I love their search, their gmail and now their calender.
Meeting my ridiculously high expectation, the design is clean and simple, yet underneath lurks the google monster -- a powerful, customizable beast.
I love toying with their monster and the most fun I had was with the natural language system. You could type "May 12 Test Drive the Nintendo Wii 3 - 7:20" into its simple side box and it would understand and input the day, time and event title. The language system didn't always pass my tests, but if always written in the above format (the simpliest I found), it will never fail. As a bonus, It even extracts words it recognizes as schedules from your gmail account with, of course, your permission to add the entry to your calendar (of course the failure rate here will be higher since other people won't know they should write their email meetings to you in a google agreeable manner).
You can have multiple calenders in colour coded layers. For example my main calender labeled "Joe" is blue. I added another calender that I downloaded from Google called Canadian Holidays (you can get many calenders, even other people's public ones) and labeled it red. So the calender is clean: my events in blue and the holidays in red. I also have the option of toggling on/off whichever calenders I choose in order to simplify the calender at will (it's important when you have many calenders; for example I added one called birthdays or you could put in your friend's or family's calendars, which they can decide what
you see off their calendar.
Of course like always, every program Google makes has incredible search features so you can always find any event you made.
Another cool feature that I will no doubt never use, but if I was a popular, social guy, I would find indispensable is their invitation feature. It's basically Evite.com integrated into their calender system. You can invite anyone with an email and they can update a dynamic list of their intended attendance. Guests can also write comments and/or invite more people. If you have gmail, the email will look fancy and you don't have to go anywhere, but if you have, say, Hotmail, you'll get a link to go to. I tested the service by inviting my Hotmail self to an imaginary party and I told myself that I would come and everything looked and worked great. I even tried to cancel the party on myself and it gave me the option of sending an apology letter to everyone or don't tell anyone.
If you are always connected to the internet, then an internet calender makes sense. I basically wake up every morning, check my email, look at my desktop for the weather and now check my calendar. The only requests I have is that they include a To Do collapsable side panel or a To Do Tab along with their different views (day, week, month, customizable length, agenda) and a gmail icon to tell you if you have mail or not, and if I'm really picky, the settings option of including gmail chat on the side. It is, however, only in the beta stage and usually any request I have, they somehow seem to meet it.
Anyways, if you're interested, go
HERE.