Pool Story and a new 21-Day Challenge

I had one heck of a workout today.  Hopefully, I mitigated some of the damage I caused by eating fondue last night.  I'm starting a pretty lame 21-day challenge on Monday.  I'm going to make sure I drink the recommended 8 8-ounce glasses of water a day.  I know it's boring, but it's something I've been neglecting to do. 

Here's the pool story I promised yesterday.  It happened the summer between my freshman and sophomore years of college.  I had been swimming at the pool in town early in the mornings before work.  It was usually pretty quiet.  Maybe me, one or two other swimmers, and the lifeguard.  Occasionally, I'd arrive a little later and there would be a few more people there, but there were always a few lanes open.  One day I got there and caught a glimpse of another swimmer who seemed to be trunkless.  I told myself there was no way anyone would do that.  He must have a flesh colored suit or something like that.  Then I saw his swimming trunks at the end of his lane.  I glanced up at the lifeguard.  She was very focused on her fingernails.  The worst part was the only lane available was right next to the guy.  I wasn't sure what to do.  I got in the water and tried to forget about the naked guy right next to me.  Seriously, who does that?   

21-Day Challenge: Complete

I just finished my 21st day at the gym in a row.  Working out should now be a habit.  I'm proud of myself.  I'm ready for a rest day but I'm going tomorrow so I can have one more workout before my weigh-in though.  I want this to be a good weigh-in but I'm a little concerned that I stuffed my face just a little too much this week.  We'll see I guess.

The results of exercising every day have been amazing.  Since I started my 21-day challenge, I've lost at least 7 pounds (I'm going by last week's weigh-in).  I've also discovered the hard way that having at least one or two rest days a week is a necessity.  My hamstrings are constantly sore, my knees hurt a little, my back hurts, and my arms are always sore.  I need to let my body recuperate a couple times a week. 

So now that this challenge is over, I need your suggestions for other 21-day challenges.  Here are some ideas I've gathered so far:

Count/plan my calories every day
Cut out one item from my diet that I love but isn't very good for me (i.e. pop, chocolate, etc.)

That's not much, and I'd like to do a challenge every other month, so I really need suggestions.