GmailAgenda is an awesome new experimental add-on for Firefox that will integrate Google Calendar into your Gmail account. No mater if your using a regular Gmail account or a Google Apps account – this should work for either one.
As far as customization goes, you can change the embed width. The Google Calendar embed can also be expanded and collapsed as needed. Also, You can choose which calendars are shown/hidden for each Gmail account.
The last thing worth mentioning is there is a “Quick Add” feature, not available for Google Apps accounts, that will allow you to quickly add events to your calendar.
Want to try it out? You have two alternatives:
So how does this rank against Gmail’s announcement of adding the calendar in as a gadget for Gmail? Which do you like better?