If you've been living under a rock for a while, then you don't know Thunderbird is basically Mozilla's attempt at an e-mail manager. It basically has all the same pros/cons as Firefox, relatively stable and barebones, with access to a tons of add-ons for increased functionality. I've always wanted to use Thunderbird/Sunbird (Mozilla's Calendar App), but with no direct integration with iTunes/iPhone, I forgot about them. That is until I found this awesome guide:
bfish.xaedalus.net » Stay in Sync with GCal and Thunderbird.
The guide details how to get Thunderbird working with Google Calendars. If you can't bother to click on the previous links, you accomplish this using these 2 extensions for Thunderbird:
Lightning - Project Home
https://addons.mozilla.org/en-US/thunderbird/addon/4631
Lightning adds Calendar functionality into Thunderbird, and Provider lets you add online calendars into Lightning. Add those 2 together, and you have full access/control of Google Calendars through Thunderbird.
Where does this iPhone comes in? Through:
NuevaSync - Over the Air Synchronization
I'm sure most of you know or have seen this site by now, but basically it provides free push functionality from Google Calendar + Contacts to your phone. It's pretty plainless to set up and it is a work on progress (no public calendars, no distinction of multiple calendars yet) but it does the job.
So add it all together and using Thunderbird you can manage your Google Calendar which get instantly pushed to your phone thanks to NuevaSync.
As someone who HATES Outlook (hate hate hate Outlook), this is the best thing I've found for my phone this month. Hope this is useful to others.