Posted on 05 August 2008 by Christine B.
Sometimes keeping things simple is the easiest way to ensure you don’t miss your appointments or lose all your data to a technical screw-up. The most basic way to keep a calendar would still be the good-old-fashioned pen and paper approach. This comes at a price though: not just the minor cost of purchasing a new calendar each year, but mostly the cost to your back from carrying it around every day.
A more back-friendly option is a digital calendar, and virtually any computer, phone or PDA you buy comes with such a device built in. The problem is that you need to either decide which of these devices to use as your calendar, or find ways to sync the same calendar onto different gadgets.

Keeping an online calendar
If you keep a copy of your calendar online, the obvious benefit is that you can access it from any computer, anywhere in the world. For those who commute to different offices or locations for work, or have off-site meetings and are generally not always carrying their laptops with them, this is a nice back-up option.
Similarly, if you sometimes find yourself without your laptop but need to add a quick appointment to your calendar, online storage is an easy solution. One simple but versatile system is Google Calendar. However, when keeping track of your daily appointments through different calendars, how do we get them to sync up with each other so you are not referencing three different sources all the time?
Syncing Google Calendar with iCal
It’s extremely easy to sync your google calendar with iCal (for Mac users), but it is only a one-way sync from google calendar, to iCal (not the other way around).
The only way this is useful is if you want to use Google Calendar to simply add appointments to your iCal, and not actually use it to reference all your calendar data. If you would like a mirror of your iCal information to be available in Google Calendar, then you need a two-way sync.

Two-Way Sync with GCalDaemon
If you are the experimental type, then the command line, cross-platform, beta-release application called GCalDaemon will get your blood flowing. Like any good open source application, the secret to setting it up lies in being comfortable editing the text configuration file. Lifehacker has a great description of this trick here.
Keep in mind GCalDaemon is compatible with both Mac and Windows, and can sync your calendars across multiple applications such as: Lightning, iCal or Rainlendar

Two-Way sync with Spanning Sync
Easier for the non-programmer than GCalDaemon is Spanning Sync. Spanning Sync does charge a subscription (or one time purchase) fee, but if you refer a friend you receive $5, and your friend receives a $5 discount. This can add up to a free subscription, or even some spare cash. There is a free 15 day trial version of the program, and you can subscribe for $25 per year, or pay $65 once for lifetime use.

Two-way sync with BusySync
Cheaper than Spanning Sync, BusySync offers two-way synchronization between Google Calendars and your iCal, as well as calendar sharing through a LAN connection (think: sharing your calendar with your assistant/secretary or between family or coworkers). It comes with a $25 price tag, and has a free 30 day trial.
Syncing your calendar to a mobile device

If you want to sync your Google Calendar to your mobile phone or PDA, then GooSync is your program. The supported devices are nicely listed, and pictured, here. Not surprisingly, the iPhone is among the supported cell phones for GooSync. There is a free version of the program, as well as a paid version to get more features, like the ability to sync your task/to-do lists.
To choose which option suits your needs best, consider whether you are using a Mac or a PC, and whether this means you are already automatically syncing your calendars with some device or another: some phone software allows you to sync information kept in outlook, while iCal can sync with any iPod you may already carry with you anyways. When it comes to inputting extra information, the iPod sync is not very useful, it only serves as a reference of what is already added to your iCal.
Ultimately, you would likely benefit from a Google Calendar to computer sync, as well as a sync between your computer and mobile device (cell phone or PDA). If you use your computer as a ‘master file’ of all your appointments and day to day activities, and sync these to both Google Calendar and your mobile gadget, then you can be sure you will always carry the most recent copy of your calendar with you, no matter where you are!