Skillerz is my all time favorite PTP site, as it is about the only PTP site (aside from this one of course) that pays out in bitcoin and is completely legitimate, you actually have a choice in fact, you can either exchange your in-site points for either cash which is sent to your paypal, payza accounts etc, or you can exchange them for bitcoin which you can transfer directly into your bitcoin wallet of choice etc.
Currently I have made a little over 0.05 from this site, it is compatible with hitleap and otohits etc, it is well worth using give it a shot :)
