I did not put the effort before to keep a calendar of any sort on the computer before since it was a pain to get it to synchronize between the desktop computer, laptop, and if I am not near those two the calendar is unavailable... until I found a killer combination.

Thunderbird + Lightning + Provider for Google Calendar

This was so good it was enough reason for me to switch from Evolution to Thunderbird... the interface for Lightning seems a little out of place compared to thunderbird and gnome's default theme... but I can live with that. Now adding a event in my laptop, desktop or google calendar online is all I need to do and the other places are automatically kept up to date. Fabulous!

I had used other calendar synchronization application combinations before, but this is by far the best one I have come across and highly recommend you to take a look. Enjoy!