Reliablecom, a provider of cheap Calling Cards to many international countries and Voip Softphones to US customers is running specials every day. One special, it runs on Thursday is calling to any part of India at just 1.9 cents per min all day. Call quality is good now. They come with different offers each day but Thursday is the best.
UPDATE: They are running this promotion on Wednesdays too.
Product Name: India 1.9 Daily Special
Card rate Local mins toll free access minutes
$20 1.9¢ 1053 mins 588 mins
$10 1.9¢ 526 mins 294 mins
$5 1.9¢ 263 mins 147 mins
Please note that the call rounding is 3 minutes so make sure you talk for increment of 3 minutes to take most out of your money. You can enjoy the feature till 90days from the first use . If you are looking for low rates on calling cards, they have very low rates.