Google's finally put out an iPhone-friendly version of their Google Calendar, allowing you to add, view, but not edit or delete events from your phone. Of course, you could get this kind of functionality by syncing GCal to Calendar or Outlook and then syncing to your iPhone, allowing you to add, edit, and even delete events. But if you're one of those who insist on using only Google Calendar along with your GMail, this seems pretty usable—not to mention fast. [Google Calendar via GMailBlog via MacApper]
This works well for me. I don't sign in to Gmail or do any time-consuming or complicated set up either. I just put the Google iPhone apps on my front screen of my iPhone, it's easy, just to to the "Apps Store" (click on the icon Apps Store on your iPhone), then type in 'Google Mobile App' and download it. Now you click this app and you can quickly access your calendar, and other very cool things (Voice Search; Search for restaurants-movie-businesses-etc. by you without having to know where you are; easily access other Google products like Gmail, News, Weather, Maps, etc. I don't even have 3G or broadband and use it all the time. Very easy and little clicking (unlike this confusing sounding iCal and sync stuff).