Staying productive when working from home can sometimes be a challenge, especially when I'm working on projects that aren't necessarily for a client, but are more self-assigned. I recently discovered mytomatoes.com, which employs the Pomodoro Technique: 25 minutes of work, then a five minute break, and after four "tomatoes" a longer break. Every time you complete a "tomato" and hear the alarm, you log what you worked on, so it's really great for accountability.
Using mytomatoes.com is what motivated me to have a day free of social networking one day last week. I realized how much time I was wasting on Twitter and Facebook and I needed a break to increase my productivity! For me, it also does double-duty — I need to track my time when I'm doing work for clients, and this way I have a reminder to log what I work on for every 25-minute increment (instead of remembering at 4pm that I should have been tracking my time for the last 7 hours. Oops).