How to Choose a US-based Online Degree?

Catalin Braescu asks: "I have an Egyptian friend which wants to finish highschool in US, using an online degree institution. Her American BF advises her to go for Keystone, but I really don't think she can later on be admitted to any college with that kind of diploma. So I am asking Slashdot if there are any good resources online (or at least some easy-to-understand checking points) to verify whether any online diploma is good for going to college or is just some worthless paper. Being from Europe, I can hardly know such details myself - and the same issue can be applied to online college degrees, too. HELP!"