I'm a paying memeber on the site and I really love it! You can track your foods, set calorie limits, track water, steps taken, exercises. You can list goals for yourself and get great advice and a lot of other stuff I still didn't try.
I mainly chose to join because the calorie database is a lot more accurate than sp*rk people or any other online diary I've tried before.
I've attached a screen capture today's diary (the page is too long so I cut it in half). hope this helps