Donations might be a better way to make a little side cash.

It's a very slippery slope when you get into charging for media content..

I would say using Mixergy as a springboard into something else, like a product, as Joel used his blog as a springboard for Fogbugz.

You also have a great setup for doing promotional stuff but obviously you need massive numbers to make any real money that way.

Best of luck in any case.