When I first heard about Popfly I didn't really grok it but now I've had a week or so to play with it and try to make sense of it... it's really cool.

Everyone talks about mashups and how they're changing the rules on the interweb... but too often it still means a lot of laborious programming and testing and delving through API documentation.

Yahoo! Pipes was supposed to make it all better, and if fact from a programmers perspective it's certainly made things easier.

Where Popfly really shines though (and I totally agree with Chris Pirillo on this) is that it makes mashups a totally graphical, drag'n'drop no-code experience that even I can get my head around....

15 mins after signing in I had my first mashup running (Virtual Earth showing the 5 latest Twitter posts updated every 30 seconds)

Once you've built a Popfly mashup you're not limited to running it on the Popfly site. You can embed it on your own site, or on Spaces or even download it as a Vista gadget.

Even at this very early alpha stage the capabilities of the basic no-code tool are pretty fantastic. Add to that the very simple coding language they've implemented and anyone who can code in JavaScript, PHP or VB/C# is going to have no problems extending this.

I can only imagine the power that's going to roll into here as the team add more blocks (wrappers for APIs or output/display mechanisms) and fine-tune the UI.

As an example of what Silverlight can do (itself still a product in development) it's even more impressive - a Microsoft team really eating our own dogfood (and finding that it tastes just fine!)