I think by far one of the cooler features that Google offers is their domain apps… for free!
I’ve recommended it more than a few times and use it for several of my domains. I basically use it just for the mail features. You get the Gmail style layout with your own @sillydomain.com or whatever address. No account limit! Just that alone would be more than great but they’ve also have domain oriented docs, calendar, etc. too. Real easy to setup, after you have a domain name you just need to point your DNS settings at Google servers.
Check it out: http://www.google.com/a/
