I set out to pay a fee to pandora.com (highly recommended, BTW, and available for free to people who don't use it a huge amount). The page where I was to enter my credit card number showed a URL that started with "http://". So I sent them a note and asked. They replied:
"The tuner embedded in the site is a Flash application is 'https' secure. . .
Our site has been approved in its current form by FDC (parent company of Linkpoint) on behalf of Visa/Mastercard/Discover) and also separately by American Express. Amex is particularly picky about security, by the way.
I understand that a mixed mode page can be confusing to some users. The technique has become much more common as active content sites have proliferated. By all means, the hyper-cautious are welcome to add an "s" to the url before proceeding."
You can download 8 basic lessons, and then after that you can purchase lessons from famous musicians on how to play popular songs if you want. It even has a built in tuner to help you tune your guitar. I just wet my pants.