Who here meditates every day? How long do you meditate for?

Just this week I've made an actual effort to meditate every day...twenty minutes or more if I have time, but I shoot for at least 10 to 15 minutes. Until I actually started doing it, I didn't realize just how much time even 15 minutes really is.

For those experienced in meditation, when you first started your practice how long was it before you saw noticeable differences/effects from it?