Problem: I need to drive to appointments, pick up gear, etc. during the work day, and changing in and out of cycling clothes isn't an option.

Solution: I leave my car at work for daytime driving, but bike back and forth to work. Good motivation for riding on rainy days (no choice, the car is at work). On nice Fridays, I can either drive home with the bike on the roof, leave the car at work for the weekend, or get a lift back for the car after riding home.

Probably wouldn't work for everyone, but works well for me.