As an accomplished procrastinator I have been dealing with this issue with varied levels of success since leaving my home university (and the potential for running into a disappointed member of my committee on the street). :)
I agree whole-heartedly with J. Lund's suggestions. And even if you don't have an office, at least shower and dress for the day! I don’t care if you will just be mumbling to yourself in your tiny apartment as you try to rewrite a draft of something for the hundredth time. Don't be a graduate student stereotype! :)
Visiting scholar positions are helpful in keeping you on track. They can also be imperative if you are doing work in other countries and need to keep that visa active! Through my visiting scholar status at the University of British Columbia I have been able to meet and connect with professors in my field of study, make connections with other graduate students, organize a panel with graduate students and faculty at a conference in Canada, and audit several classes. These things definitely keep me in line and (somewhat) on task. Being a visiting scholar also has the added benefit of introducing you to the culture of other universities. I think this exposure is an added benefit in the job market because it will teach you to be flexible and brace yourself for culture shock when you end up somewhere unlike your home institute.
I am also a big fan of writing groups. I have been involved in one for almost two years now and it has both a) made sure I make my deadlines and b) improved my writing tremendously. I always feel newly energized after a meeting with my writing group - much like when you run into a friend at a coffee shop on campus and swap ideas. My writing group is completely "virtual" in that we meet on skype once a week, so you don't need to make it local by any means. We are all "orphans" from our home institute and I think we all get a great deal out hashing things out together.
Think outside the box - most of my friends in Vancouver are musicians and artists - not academics. But that doesn't mean they aren't thinking about the world in interesting and (often more) meaningful ways! I have quite a few friends here that are interested in urban studies and I started a book club that meets monthly to discuss books (both academic and non-) on urban issues. Last month we read Brown-Saracino's book which was something I needed to read for my own academic scholarship and was also really interesting to discuss with anti-gentrification activists and artists. I am a big fan of breaking down barriers between academia/non-academia so I have found this to be a fun and interesting way to engage with other about my own work and the larger context within which it sits.
Finally, I track my hours. This means I track how many hours per day I work on dissertation related things and what those things are. Not only does this give me a visual warning if I haven’t been making much progress during a week, but it also lets me know HOW I’m spending my time. If I find I am spending way too much time on “maintaining relationships with informants” (otherwise known as drinking in bars with people who know more about your topic than you do), I lay off it for a little while and dig into the always fun, interview transcribing…
Good luck!