We posted our experiences of three of these here - http://www.untitledstartup.com/2010/02/accepting-payments-on-the-real-time-web/ http://www.untitledstartup.co

We posted our experiences of three of these here - http://www.untitledstartup.com/2010/02/accepting-payments-on-the-real-time-web/ http://www.untitledstartup.com/2010/02/accepting-payments-on... We ultimately chose to go with recurly, but are going to look at chargify again once they stabilize a little bit. Recurly is not on the list, but in the process of doing so (I just emailed them ~10 minutes ago specifically about being a validated service provider).