My T-mobile G1 phone came in the mail today, marking a significant point in my shift away from proprietary technology. I've been heading this direction since about August of 2009, moving bits of data at a time from local storage (Exchange/Outlook/Thunderbird/Word) into “the cloud” (mostly Google apps of one form or another). My Windows Mobile phone (an HTC TyTN II, a.k.a. AT&T Tilt) was the last bit of Microsoft-only technology, and now it's been replaced by an Android-powered G1. So far, I'm really liking it. (Side note: I actually have AT&T, and the G1 is unlocked, in case anyone was wondering).
Let me say first of all that I didn't do this out of some anti-Microsoft vendetta or anything like that. I did it because I like how it works better. It's less work for me to maintain, and easier and faster to access from anywhere, especially Gmail and Google Docs. Gmail labeling, automatic spam filters, and perfect integration with Android make it vastly superior, in my opinion, to using POP3 and an OS-based mail application.
The full list of significant replacement applications is this:
Exchange/Outlook -> Google Calendar
Thunderbird/POP3 -> Gmail
Word -> Google Docs
Excel -> Google Spreadsheets
SharpReader (RSS) -> Google Reader
Now, this is a pretty short list, and it also probably doesn't have all of the same correlations as your list might have, if you were to make one. Lots of people use Outlook for email, but I skipped that feature because I prefer Thunderbird. In addition, Google Docs and Spreadsheets are not suitable if you have very complex and macro-enabled or formula-laden documents. But for a good 95% of my needs, it's completely adequate, and usually a genuine pleasure to use because of how easy it is. The list also comprises the majority of things that I spend time on with my computer, aside from work. All of the data is stored online, meaning I can get to it from anywhere with an internet connection. I can stop working on something on one computer, even a draft of an email, and finish it on another computer, or even my phone.
A notable caveat here is that I am not completely comfortable with storing private data on Google's (or anyone else's) servers. The tiny bit of stuff I have that falls into that category stays on my computer. But I almost never need to work with those sorts of files, so they don't really factor into the usability equation much.
One other key point to using Google for all of my data like this is that it's extremely accessible. By that, I mean I can import and export ALL data using freely available tools at any time. It also uses open standards for data access, meaning it's very easy to integrate with other applications. There is a huge set of web applications that interface directly with Google apps, and new ones are being written all the time. This greatly increases the chance that you can find an application that does exactly what you need, instead of being stuck with the latest Outlook release.
Once again, I have nothing against Microsoft, and their suite of management tools is appropriate for some applications. I just like Google's offerings better, and they seem to be improving rapidly. It just takes a little time to make the shift. It's worth it though.