[Freeswitch-users] Developer friendly SIP trunk provider for experimentation?

I'm just getting started with FS and want to hook up a couple of SIP trunk for experimentation. Right now I'm looking for a provider that'll let me pick numbers from a web interface and pay with credit card. Many of the providers I come across when googling seem to only sell SIP trunks in bulk and want me to contact a sales rep to get started. That might make sense later on in the project but right now I'm looking for something more light weight. Any tips?