Living in Gworld
Dan asked me to post an update as I explore deeper into the Google forest. I'm now fully committed to Gmail and Google Calendar (why isn't it GCalendar?) and Outlook is now purely an evil tolerated for work purposes only.
And with Rob Howard's tweet this morning about Google Apps for business, perhaps that's only temporary! Go Rob! (lol, while searching for Rob's blog URL, I found that he's already blogged it too)
Gmail
Using Gmail is great - it's everywhere I am, unlike Outlook that tries hard but is never going to be as ubiquitous as a browser. I continue to love labels over folders, i don't miss the heirarchy simply because all mail is there, never deleted and SEARCH ROCKS. It turns out that I was filing things away in folders in Outlook really only so I could find them quickly. If finding them is super quick, that issue goes away.
So labels rule.
Filters rock too - my aim is to keep everything out of my Inbox that isn't urgent. Therefore every time I get an email I think "is this important enough to interrupt me?" and if it isn't I create a filter to move it out of the Inbox and to a label. I can leave it unread or mark it read depending on if I ever *need* to read it. Some emails are just for filing, so I don't even see them. Perfect.
Some I label, but leave in Inbox because they are something I want to deal with today.
Regardless of the filter, the end result is the Archive button. I don't plan on deleting anything. Spam will delete itself. In fact I posted a suggestion to the Gmail team that they should replace the Delete button that is sitting in prime real-estate with a Mark as read button - something that I think is far more useful. I subscribe to a few mailing lists and want to mark as read all the time.
I setup my Gmail as follows. I have two POP3 accounts that I want sucked into Gmail, so I went to Settings > Account > Add another mail account. I entered the POP3 login info and told Gmail to delete the email from the server (by unchecking the "leave a copy" box). That's it. Gmail sucks in my email in a clever way - if you get a lot of email from an account, it checks more often. Quiet accounts it checks less often.
The only other trick I can pass on is the "Send mail as" option. I noticed that some mailing lists only accept mail from a specific email account (others don't seem to care). Plus I use a lot of email aliases (e.g. dell-at-shawthing.com I use with dell, but it's really just an alias for my real POP3 account). It's nice to reply to some people using the aliases they send to, so for my most popular aliases like @coveryourasp.com I set those up under "send mail as".
Just click "Add another email address" and type in the email address. You have to verify it of course. I also check "Reply from the same address the message was sent to" so that most of the time people aren't even aware that I'm using Gmail. If you send to james@britishinside.com, that's who the reply comes from.
Oh, and don't forget to click the Chat tab and move it below the labels. 
Google Calendar
I love the calendar too. I like weekends together so I set Monday as start of week.
Setup is much easier - I created a gmail account for my wife too, so she uses calendar as well now. We share our calendars with full privileges ("Make changes AND manage sharing") so she can add to mine and vice versa. Our calendars are not public though. But I see hers and she seems mine - in pink and blue so it's easy to tell what's what.
This morning Tara created more calendars on her account for our kids, and shared those too, so now I see calendars for the kids baseball, softball, teacher conferences, etc. I chose that sandy color for those. It's awesome. We all see everything at once and can search for events easily.
Note that you won't need to invite each other to family events any more! Just put them on the calendar. if you invite your spouse you'll end up with two of them on there, in pink and blue. 
Creating events is great too - it's so clever that you can just type "7pm Maisy softball at Alex field" and it picks out the time, description and location automatically. You can choose which calendar you are creating it on.
Wow, I'm kinda pissed actually that this was out here and I was stuck in Outlook all this time. Guys, when you find stuff like this, tell me!