Good design always benefits from a feedback loop between users and those doing the designing, and the tighter that loop is, the faster a service can learn from and adapt to its users. Google’s newly announced Gmail Labs is clearly an attempt to do this for the popular Webmail service. Google is adding a new tab called “”Labs” that allows users to try out all kinds of new features and then immediately let Gmail developers know what they think. So what, you might be thinking. Isn’t the Gmail service already in beta anyway? In other words, it’s already in testing mode, so what makes this any different?

I don’t think Gmail Labs is that different — it’s just more feedback, faster. Obviously, anyone who uses any Google app or service can send an email to a support address, check an online forum, use something like GetSatisfation, or check support groups or FAQs. But how many users give up before they do all of those things? That’s feedback a designer or developer could use — and eventually, they will probably get it. But the faster it comes in, the faster a service can be smoothed out and made more feature-rich. That’s part of what makes Web services so different from shrink-wrapped software.

It reminds me of Daniel Burka’s presentation from meshU a few weeks ago: In it, the PEI-born Digg designer used one of my favourite metaphors for iterative, evolutionary design — a story that comes from The Whole Earth Catalog many years ago, in which an architect laid out a university, but didn’t put in any sidewalks. Instead, he waited to see where people walked and then paved that. The lesson, in other words, is not to try and anticipate all the ways someone might want to use your service — see how they use it, and then focus on that.

A couple of days ago, Garrett Rogers of ZDNet posted an item about something interesting he found while poking around in the Javascript source code for Google’s Gmail: the word “domain.” Putting two and two together, he theorized that Gmail would soon be offering a hosted email solution for anyone with a domain of their own – such as a corporation, for example, or a university. In other words, Google would be your email administrator, but the email would look like it came from your domain.

Nice work, Garrett – because that’s exactly what Google has done. First there was a note on the Google blog about the company providing a hosted email service for San Jose City College – which was spotted by eagle-eyed Nick Carr of Rough Type, who posted a comment called “Google attacks Outlook.” In case you thought he was exaggerating just a tad, Google then put up its hosted service beta, which was spotted by the equally eagle-eyed Paul Kedrosky.

Not to be inflammatory, but I think this is huge. Yes, some companies will be concerned about letting an outside provider host their mail, just as there are people who don’t use Gmail because they don’t trust the company, or don’t want even robotic eyes looking through their messages – or because they are worried about the government forcing Google to deliver email to the authorities.

Despite all that, I think there will be plenty of companies – particularly small ones – as well as universities and other users who will be more than happy to get out from under the thumb of Microsoft Exchange/Outlook, although as my friend Rob Hyndman notes, the MSFT package still has a lot of things that Gmail doesn’t when it comes to being a PIM. Phil Sim of Squash, meanwhile, thinks that hosted Gmail is just one more tool to lock you in, and Zack Handley says that many companies would probably find that Gmail is more than enough.

See my update here.