The social micropayment startup Flattr has rolled out a change to its service today. As we first reported last month, users of the site can now donate specific amounts of money to Flattr users.

Flattr lets users "Like" websites and content, but that action is backed with real money. Before this new donation feature was added, the money in your Flattr account was split evenly each month among all the sites you've "flattred." And while you can still use the service that way, you'll also be able to donate a specific amount - a minimum of €2, up to €50. "We think this will take the system to a whole other level beyond just tips," says Flattr's Eileen Burbidge.

On every user-profile page, you will now find a "Donate" button. Click it and you can give some of your available means away. This donation can be made anonymously.

As we suggested last month, Flattr's new feature will likely benefit WikiLeaks, as Flattr remains one of the only ways to make a donation to the site now that PayPal, Visa and MasterCard have closed those paths to funding. Beyond the support for WikiLeaks, Flattr has developed a small but thriving network of users: since opening its beta, it has gained 46,056 registered users and has passed more than €114,057 through its peer-to-peer payment system.

If you're still looking for more ways and more things to Flattr, a developer has taken Flattr's API and built Flattr4Android, a tool that will let users scan a QR code off-line. This code is tied to a Flattr account, making it easy for you to submit and flattr content via your mobile phone.

With these changes, Flattr address two things poised to be big trends this year: the growth of mobile money and expansion of peer-to-peer networks.