Messaging and Talk Applications
You can get all of this for $50 per user. The email limit is 10GB and things can supposedly be made ad free. They are also guaranteeing 99.9% uptime for email.
This looks like a pretty good deal to me. There are some reservations, but at an early step forward I think this is a strong start. Several years ago Microsoft stated that common applications would be hosted on the web. And while Microsoft has their Windows Live, it appears that Google is much more structured and organized in their pushing these applications to the corporate customer.
I have recently started making more and more use of the Google Calendar, Docs and Spreadsheets. The Calendar largely due to some repeated issues I have been having with my PDA. I was tired of it failing while I was at home over a weekend and not having any calendar or contact information, so I finally started making more use of the calendar and contacts portion of the Google apps. I have also started using the Docs and Spreadsheets more often as well. I find it convenient to access from multiple computers and operating systems. The links they have added to GMail to open documents in Google Docs has been pretty useful as well.
I am still not comfortable with certain confidential documents up there though, so that is a limiting factor. I also have some issues with margins in certain docs when I print them. I may just be overlooking a setting though. I am looking forward to seeing these hosted applications expand in the future in their features.