I love that too, we sit there and talk to her and say simple words to see what her reaction is. She babbles and coos a lot now, and she tries to imitate some words. If we say "Hiiiiiii", she'll try to say it. Not quite there yet, but in a month or two I think she'll have it. She's particularly fond of the "G" sound, everything starts with "Guh" and is followed by some other weird noise. lol!
It's really amazing how fast they learn things...just a few weeks ago she was quiet, didn't smile, didn't laugh, didn't coo, and was basically this little sleepy lump. Now she's bright eyed, grabbing things, watching TV, cooing and interacting, holding her bottle on occasion, standing up if she holds our thumbs...it's crazy.