Podcasts!

This is possibly the most fun you can have on the web after YouTube.

Seriously... where else can you find stimulating conversation on a variety of subjects from physics to dating, from music programs to music discussions, 24 hours a day, 7 days a week?

And the best part? Most of it - 90% - is as free as the air.

That's right; installing special equipment (for the most part). You plug in your headphones (or not) and start listening.

And if you're feeling really creative, you can create your own podcast.

(I wasn't feeling too creative, so here's my favorite podcasts so far - Intellectual Icebergs -http://podcasts.yahoo.com/series?c=e&s=1c42803686415ef2e925fe8e0ac3ec01&es=1&rs=1)