Every year for lent my family gives up eating out. With two kids and two careers and a busy schedule this is a huge sacrifice for us. Sometimes its so much easier to stop and pick something up or order pizza or just go where someone waits on me for a change...
There are positive side effects, of course. We spend a lot more 'dinner table' time together, I get to actually use all those skills I picked up in culinary school, and every year my husband loses about 10 pounds and I shed 4-5 as a result of the healthier fare we're eating.
Edited to add: We also each pick something positive to commit to doing during Lent. This year, I'm writing a letter each day to someone in my life whether they are far away or live in the same city (or house for that matter).