Synchronising iCal and Google Calendar

I use primarily Google calendar for everything because I need to share a lot of my data with other people who don't use Macs. However, I prefer the iCal iPhone app to the Google Cal app, and would prefer to do everything in iCal and sync to my iPhone with iCloud. So I'm trying to get iCal data to work interchangeably with Google.

I've figured out how to import iCal calendars into Google Calendar but new entries in Google don't show in iCal and changes to iCal don't materialise in Google. Is there any way to synchronise these calendars properly in both directions so I can edit in either app?