There are plenty of easy-to-use apps available on our mobile devices to do the same. I personally use the following: Evernote, MyFitnessPal, VirtuaGym, and Facebook (for moral support). Friends recently suggested I try a running app called Runkeeper since I've taken up jogging recently.
The great things about apps like MyFitnessPal and VirtuaGym is they provide me with reports that let me see a graphical representation of my progress. Seeing MY success graphical gives me a boost of confidence. (You can learn more about these tools in my eBook, Use Your Smartphone to Lose Weight.)
Pictures ARE worth 1000 words
Graphs are great, but before and after pictures are awesome. Put the two together, and you have the best motivation you can provide yourself.
Cisna's team documented his transformation with video and photos. They have put together a mini-documentary to showcase their study. I am currently in correspondence with John Cisna to get the link to the documentary to share.
Tracking progress may seem mundane, and not worth doing, but this is probably the most crucial habit to develop and it is second only to actually doing exercise and eating within reasonable limits.
Do you have written goals? What tools do you use to track your progress towards your goals?