How can I sync my Google calendars with iCal with iPhone?

try: http://www.google.com/googlecalendar/new.html

Ya, that’s great, but I wanna maximize the calendar feature that comes with the iPhone, not the browser.

Calaboration is a great tool that helps you sync your iCal with your Google Calendar. Whenever you have internet access, iCal and Google will talk and sync events. As long as your iPhone is synced with your iCal regularly, all three will be synced.
(You can get rid of Calaboration once you’re synced. It’s just a setup tool.)
You can set up however many calendars you like.

WOW. Thanks @lefteh ! That was exactly what I wanted. Lurve to you!

I do this all over the air using Calaboration to sync iCal with GCal, but using Nuevasync to wirelessly keep my GCal syncd with the iPhone (it uses the exchange protocol). This is incredibly useful and means I only have to sync my iPhone by cable when I want music or a backup (or contacts, which I don’t bother syncing with Nuevasync).

I’d highly recommend this. Me and my Fiance both run it, and subscribe to each others calendars on GCal. Our events show up on both phones within a minute or less of being added on the other’s phone. Absolute genius.

@benseven I agree. I use it and I think it’s great for multiple calendars.