One way to motivate yourself to ride more is to pick a challenging goal and then track your progress towards it. Here are some examples:
1) Roadies in DC are challenging you to ride a Century per Month
2) Transport cyclists in DC are challenging you to use your bike to replace 30 car trips per month
3) Clif Bar is proposing the less intimidating "2 Mile Challenge," where you make a commitment to replace some of your short-distance car trips with bicycle trips
Please share your successes or failures with challenges to increase your riding!