I've been trying out Google Contributor of late. It's not perfect, but it's the first practical micropayment service I've been able to use. If we want good content, we have to be willing to pay for it.
People could voluntarily install a browser plugin that watches for addresses and sends money. Perhaps the donation could vary by time spent on the page (monitoring for activity to accommodate leaving stuff open), or perhaps it could be a fixed sum per pageview (with a cooldown to discourage blogspam). In exchange, servers could withhold ads.