I'm addicted to Humble Bundles, I can't help it. I try and avoid most of them, but every so often there's at least a game or two in there that I want. Take today for instance, I'm a sucker for the DiRT series, and while I already have 3, Showdown was pretty cheap along with a few other games I'll probably never get around to playing (the only thing I like more than Bundles is buying games and then never playing them).
So I decide I'm going to buy the Humble Weekly Codemasters Bundle with Bitcoin. I pick my amount, click "pay with Bitcoin" and I'm presented with a QR code. Log into my Blockchain wallet on my phone (which contains only a pitiful amount of BTC, $40 or so at the current rates), take a photo of the QR code, compare the addresses and click send. One more click on my desktop and I'm done.
Disregarding the issues of having to log in to Steam for OAuth to actually claim the games, the whole thing is really quite secure and not near as inconvenient as it used to be.