Yesterday I wrote a blog post about the upcoming iOS 4.2.1 software upgrade for the Apple iPad. (iOS 4.0 is already available for current model iPhone and iPod touch units.)
In the article, I talked about support for multiple Microsoft Exchange Active Sync (EAS) accounts. EAS is a protocol that you can license and use from Microsoft to sync email, contacts, and calendar data from the email server down to a client, like an iPhone or iPad.
If you use a Google account with your iOS 4.0 or later iPhone, iPad, or iPod touch, you can keep your email, contacts, and calendar in sync all the time and across multiple devices, such as an iPad, and a MacBook Pro, for example.
If you want to learn how to set EAS up on your iOS device, just follow Google's directions found in their article: Mail, Calendar, & Contacts: Set Up Your Apple Device for Google Sync.