I swear by airset (www.airset.com) - and it's FREE and has been wholly reliable for me in the couple of years I've used it.

It syncs directly to Outlook.

When I'm at work, I enter/change schedules in Outlook on my work PC. Synchronise using the small Airset application, then later re-sync on my laptop in Outlook (then to my N95 or whatever).

The other excellent thing is that in the meantime, you can fully access your calendar, contacts (or whatever you've synced from Outlook) on their website too, with your login details.

so you have a number of options of where you enter the data (laptop, desktop, or web), and the same number of options of where to look at it.