Google recently unveiled two new updates. One update affects both Google Apps and Gmail while the other one affects only Google Apps.
The first update is support for attachments in offline-mode and affects both Google Apps and Gmail. The offline-mode in Gmail/Google Apps is using Google Gears, and is a still considered experimental. Therefor it’s located in the ‘Labs’ section.
This is a major improvement to the Offline mode and I was actually surprised when I read this announcement, as I thought it was already supported. At least to me, attachments are as important at the content.