Looking for motivation

Back in March when Jess and I ran the ING Half-Marathon, we made a commitment to each other to run the St. Jude Half-Marathon in Memphis in December. Well, the date is fast approaching, and my running is not nearly where I'd like for it to be. I've had some speed bumps that have gotten in the way (getting sick, falling during a run), but I've really let them impact my training more than they should have. I want to be ready for the race in just a few short weeks, but I fear that my training won't be able to get me there. Any ideas for ways to increase my motivation to train harder and get the job done?