Dailymile.com has a dailymission pretty much every day. It's usually just some running related question. I've never really been inclined to post answers, but I think I'll start answering a few of them via my trusty ol' running blog.
What is the one training "gadget" that you think is worth it?
Definitely my Garmin. It's pretty and green and it looks like this:
I love that, no matter where I am, I can strap it on, go out for a run, and know how far I've gone. When you're in training for something specific, and need to cover a certain number of miles, it's pretty invaluable. No more having to map out a route to make sure you go far enough. The pace information and all the other good stuff it tells you is pretty cool, but I'm trying to not worry about such things in my old age; so I mainly dig it for telling me how far I've gone.
In other news, today is our last day in Arizona. It has been SO nice to run here. I'm not looking forward to returning to the tundra.