I try not to stump too much for my favorite products, but this merits note -- Apple's new Garage Band.
Sure, music-creation software has been around for a long time... but Garage Band's innovation is that it's aimed at non-musicians -- or at least people who don't consider themselves musicians because they've never been trained in playing an instrument. People can experience the feeling of a really creative impulse made permanent -- something that used to be reserved to those willing to undergo long-time training. And, apparently, Garage Band works.
Will Garage Band will be responsible for the next great album? No. It's probably far too limited. But it could be responsible for starting the next great artist off on a career that might otherwise have seemed excessively-daunting. Even if it doesn't... making music is fun! And any invention that provides fun in new and unexpected ways is worth paying attention to -- for too long, computers' capacity to provide fun to the average user has been limited to games that are basically reflex-testers (dating back to Space Invaders, or even spacewar) or spreadsheets (from SimCity to The Sims).
The ultimate outcome might be seen only generationally -- apps like Garage Band give me hope that, for my kids, computers will be a tool capable of activating their potential in ways that have have been (over-)hyped since the days when my dad brought first-gen PCs home from work for me to play Janitor Joe on.