Tired about hearing about Web 2.0 or Software as a Service? How about this: start thinking about software integration opportunities on a grand scale, because the new AJAX-enabled Web is all about assembling the right bits and pieces of applications together to satisfy your ultimate customer.

Most people when they talk about Web 2.0 point to things like Writerly and Ajaxwrite that allow you to mimic a full-fledged word processor inside your browser, or Intuit’s various Web-based financial reporting and tax preparation software. These are all great applications and worthy of mention, but miss the point for VARs that are looking to cash in on this craze.

Instead, let’s focus on something else, the lowly programming interface. And the best Web 2.0 mashups are the ones with the sexy APIs that are getting all the coding action, like Google’s Maps. What makes VARs hot about Web 2.0 is the ability to layer a bunch of these apps and tie them together with a few clever bits of programming.

The idea is really powerful, despite the barrage of buzzwords: become more flexible and nimble with your applications, and save your clients a boat load of dough in not having to write code from the ground up for each application. Instead, design the app around a collection of already-written tools, subroutines, call them what you will.

The smarter VARs are using these combinations of various Web-based applications to piece together what they need for their enterprise customers. But it isn’t just throwing a bunch of stuff into a server and seeing what sticks. Instead, there is a fair amount of thought that goes into piecing together a “real” application out of various software layers to handle the business logic rules, the presentation and graphical interface, and the underlying data structures. This isn’t new stuff by any means — object-oriented programming has been doing something similar for a long time. But what is new is the scope and interaction of these little bits of code. There are three important distinctions where VARs should be paying attention.

First, the ability to assemble the right kind of applications is unprecedented, as legions of programmers are doing their open source thing and publishing their code on the Net every day. And as the Internet gets more applications-driven, there is even more stuff to choose from and connect to, all spread across the planet. As long as you have a solid broadband connection, you can serve up your applications.

Second, the support for developers and integrators is huge and rivals that of paid efforts from private software vendors. These days, you can grab everything that you need from various online sources instead of RTFM. There are blogs, wikis, podcasts, RSS feeds, discussion forums, and Instant Messaging chat sessions to get instantly connected with all the support and documentation and experts that you’ll ever need.

Finally, the best of breed here isn’t what is usually visible to the naked eye of the solitary browsing user. Instead, the action is under the covers. The best Web apps are being designed to be extended and have solid programming interfaces that can work with other Web apps. That is what mashups are all about. All it takes is a bit of programming skill to knit one and perl two.

As an example, try going over with your browser to Amazon’s s3 service and see what it gets you. You can’t — the idea is that you have to write the code for your apps to access the online storage repository service. This is some sweet deal when you stop to think about it. Amazon will charge your clients pennies per gigabyte, and you can rake in the big dollars developing a couple of cool Web apps that can make offsite storage really easy. They have even done some of the heavy lifting for you, and publish the code samples in a dozen different programming languages to get you started. So what are you waiting for?

For some other leading edge examples, look at how you can integrate Zimbra.com’s hosted enterprise-class email; Basecamphq.com for project management; and Concur’s expense reporting. There are plenty of other examples.

In the old days, VARs got rich and fat pushing boxes and charging fees for actually moving physical goods. In the new Web 2.0 days, the better VARs are going to get rich and fat pushing bits and doing the integration to make the Web work for them. This Software as a Service thing is gonna be huge, and the time is now to get onboard.