There's a good blog by a former tech analyst, who also happens to be my twin brother, called OnDisruption. While I don't normally like to promote something as blatantly nepotistic (is that even a word?) as this, his blog doesn't cost anything to read so I don't think there's a conflict of interest here.
His most recent posting is on the "Eight Traps of Disruption" and does a good job analyzing some of the common mistakes businesses make when they think they are being disruptive. For those who lived through the dot com era in Silicon Valley, you may recognize a few of the examples. For others, yes, it sounds crazy, but people really did make these mistakes. And often to the tune of hundreds of millions of dollars. It's often said that Open Source companies are disruptive. But it's worth validating that against a Disruption Scorecard to see just how disruptive any particular business really is. For it to be truly disruptive depends not only on the technology but also on the market, how entrenched the competition is, whether they are getting new customers and other factors. While these are just my brother's views, I think they force you to do a better analysis than just the usual gut check.
And for the truly cynical, there's a link to a Web 2.0 BS generator which generates ideas that sound an awful lot of the companies that lost money in the late 1990s. (And the astute reader can probably find similar "mission statement generators" out there also.)