One of the most interesting technological trends right now is watching the Internet appear everywhere. I'm not talking about moving from your laptop to your cellphone, but places where you didn't even think of it.
Today I went to the gym and it turns out they've bought a few Expresso Fitness bikes. These are exercise bikes that blow away your traditional exercise bikes. First, they've attached a screen and you race different routes (e.g., up mountains, through a forest) in a virtual world. You get a pacer and there are constantly others to chase. It's addictingly competitive - and you don't really notice that you're exercising (it's what the Wii Fit aspires to be). Here's a (poorly resized) shot:
In addition, it tracks all your metrics: heart rate, power, speed, calories burned, rpm, etc. - and plots many of them against the profile of the terrain you've been riding.
What's really cool about the system though is that it's web-enabled. You can create an account and track your training regimen over time and compete against other folks. Think of it as Nike+, but for biking.
I love this trend and can't wait to see where it goes over the next few years.