The Coinbase blog :
Today, we are excited to release a new bitcoin tip button for accepting micropayments anywhere on the web. The tip button can be easily added to any web page and enables website visitors to tip using a Coinbase account or other bitcoin wallet.
Coinbase introduced today a very interesting way to make tips to people.This button doesn't revolutionize anything, it's very lookalike of the Flattr button, but adds the benefit of using Bitcoins for payments, which decrease the Credit Card fees, which can be a problem for transferring little amounts of money.
The default amount is 300 bits (Ƀ0.00000300), which is approximatively $0.10 as today, and can be changed to the amount that you want. You can use your Coinbase account to make donations, or any Bitcoin wallet.
I think that Coinbase's idea is great; I've already implemented the button on all of my blog posts, if you've found some piece that you've liked, feel free to tip me.
But the biggest strength of this too is also it's biggest weakness : Bitcoin. Because mot everyone has a Bitcoin wallet with Bitcoins on it, you can't reach as many people as you could with a Credit Card based operation. This might change in a few years, but Coinbase idea is great to push people to use it.