For several years now I’ve been using www.bigzoo.com prepaid long distance calling service and I couldn’t be happier. 3.9 cents a minute within the USA and about 5 cents a minute to Singapore. Unfortunately they will no longer be offering this service after January 31st. 
So now I’m looking for a replacement service. Does anyone else here use a similar company? I’m looking for something online that I can set up and add money to my account as needed, not a calling card or “dial ten ten whatever”.
TIA
My mother tends to use www.callingcardplus.com. It gives you the rates of a bunch of different calling cards. Well, they’re not really calling cards. You prepay $5-10 a “card”. They give you the number to call and the pin online. The first time though you have to set it up and they call you within ten minutes to verify everything.
If you do decide to go with this one watch out for maintenance fees and connection fees. On really busy days (major holidays) you might not be able to get through. But for the most part it works quite well for our needs (Germany, France and Iran).
I think another one was www.masterbell.com. I think they have the pin free cards, but they tend to be a few cents more per minute.
You can get prepaid calling cards from Sam’s Club (3.47 cents per minute for ATT) or Costco (2.98 cents per minute for MCI).
Although you said you didn’t want a calling card, I can refill my prepaid ATT calling card via a phone call, so I’m not sure what advantage there would be to something you can refill online. (Also, I have the tollfree number and calling card number memorized, so I haven’t yet bothered to switch to the slightly cheaper MCI card.)
Biggest problem this person has is he wants cheap rates to Singapore. MCI Minutepass is 18 cents a minute.
May I suggest reliablecom ? I use it regularly to call home (India) and it works fine.
This link says that the cheapest card to Singapore only costs like 4.8c a minute.
www.pinzoo.com offers rates of 3.2 cents per minute on their Bronze card to Singapore. I use them for all my calling, and have never had a problem with them. However, I tend to use my cards up very quickly (within a week or so), so I’m not sure how expensive any maintenance charges can be.