3 Mother F'ing Pounds

When I woke up this morning I weighed myself and I was up 3 lbs.  3 LBS! How in the hell am I up 3 lbs from yesterday?  I've been sticking to plan so well this week and getting all my workouts in.  But 3 lbs?  Really? I know that I shouldn't weigh everyday and I shouldn't put so much stock into a number on a scale, but that seems like a big gain.  I've avoided soda and all drinks except tea, one cup of coffee and water alone.  I'm going to stay the course, but this is a very discouraging day.  I know it's a long term journey and I really need to get to where I only weigh once a week and that I'm ok with just making progress.  What other ways can I measure progress?  I know big things like changing sizes in clothing and being able to run further, but what about on a smaller scale?

What do you do to measure fitness progress?