So Google Spreadsheets is pretty damn cool - to quote GPF, "in that 'push up your glasses' kind of way."
A few people online have been throwing it some flack, saying:
a) Get over it, it's just a spreadsheet.
b) You're not safe putting your personal info here, because you can't control what Google will do with it.
c) It's less reliable than regular spreadsheets because if you lose your network connection or Google's servers crash, you may lose data.
To them I say:
a) Yes, it's just a spreadsheet, but it has one thing that is brand new to the universe: the ability for remote parties to edit simultaneously. I've been looking for something like this for years, literally. Other products have come and gone, but Google Spreadsheets is here to stay, and is wicked easy to use.
b) Privacy is something we should all be concerned about. What we need is for companies like Google to make promises in their software privacy policies that are enforceable by law, and that they can't just change on a whim. I.e. "we promise that we'll never sell or give away your data to anyone, even the government, and that it's legally yours even though it's passing through our servers". We need to raise the bar for companies so that they are expected to create a legally binding privacy agreement with protections like these. They won't do it without pressure from us (and, probably, from congress). I trust Google, generally, but that trust needs to be replaced by legal standing. If you care about this stuff, as I am, you should join the EFF.
c) It's true that networked (web top) software has one major downside - what if the network is unavailable? Sometimes you REALLY need to view and edit your data when your network connection has been interrupted, or the server is unavailable.
There's an answer for this, though, and I predict it's not too far off. What we need is software that's a combination of web top and desktop, where the desktop portion can cache and allow you to work normally in the event of a network interruption. Some apps already work like this - most major mail clients like Thunderbird have an offline mode, so you can read your email without network access (like, say, on a plane) and even write new emails (to be actually delivered when access resumes). These new Google apps - calendar, spreadsheets, etc - need to have similarly stable desktop components available, so that when the cable company digs a ditch through your internet line, you don't get FUBAR, you just get a little message saying "network operation isn't available right now - you're in offline mode until it resumes". That way, you've also got a full copy of your data locally, in case the service provider goes belly up, gets hit by an earthquake, etc.
The good news is that with Google's advances, we've entered the time when simultaneous remote collaboration on data is possible. Once people have a taste of that, they'll never go back, and pressure for mixed web / desktop answers to these problems will mount.
For now, I'm just psyched to have these new abilities. In a, you know, push-up-your-glasses kind of way.