For calls through CC, see
http://www.callcentric.com/calling_card/ . If desired, get a free dedicated access number, so you needn't enter account number or PIN. You can use their speed dial feature, instead of entering the complete destination number.
For calls through GV, see my previous post.
Neither of the above involve the OBi in any way. I believe that in most cases, you will get better reliability and quality. On most cell phones, you can program a Contact with pauses, to completely automate the procedure.
Although quality is IMO not as good as Callcentric (probably comparable to calling through the OBi), you might take a look at Localphone -- once set up, you dial a local number and it rings your contact directly. Five-minute free trial. Also Rebtel, top-quality but generally more expensive than CC.
For cheap calls to PH (or most anywhre), check out CallWithUs (quality not the best) or Betamax
http://backsla.sh/betamax (bottom of the barrel). Both have calling card features, so the OBi is not required.