The propster bar on top is a kind of preview, like with StumbleUpon. The idea is that when the tip jar begins to collect money, the recipient is going to integrate it to his website one way or another.
Is propster.me a trick page, so someone can get bitcoin donations for other people's content ?
There is no trick, however you made me aware that there was a point of confusion: when user navigates inside the iframe to another website (for example http://www.google.com), the toolbar seems to say that if you click on the Tip button you will give a tip to Google. Although the tip jar popup still says that money is going to "Programming M**ers", someone could miss that. But I just FIXED it. Now, when the Tip button is clicked, the iframe automatically returns to the original state, to the "Programming M**ers website.
Btw, a programming tip: if anyone is wondering how it is possible to know that cross-domain iframe url has changed, here is the trick: compare the values of history.length at different times !
To see this in action, look at the source of the page in the original posting. 
