L.S.
I have not tried either of these programs. Both my kids, before they were two could recognise all their letters, both uppercase and lowercase. My daughter (who is now three) knew all the sounds of all the letters well before she hit three. She is now three and a half and beginning to put together words by sounding them out.
My secret? The computer. Fisher Price has a great website that changes letters whenever the child presses a key on the keyboard. (you don't need to know how to use the mouse) Google, "toddler games" and you will find it.
THe other site is www.starfall.com. You will need to teach your child how to use a mouse. This goes over letter sounds all the way to stories. Both my kids love this one.
I let them do what they want when they want. They really just picked up all this stuff on their own with the computers help. All i really do is reinforce it when we are driving or whatever.