Though there is a bus that will take you from downtown San Diego to Julian, the easiest way to get to Julian is by car. During the Apple Festival and on busy weekends, finding a parking space can be difficult. Visit during the week or "off season" times and there are plenty of places on the main street or up one of the small side streets.
Walking is the best way to get around Julian, but there are a few interesting things to see or do outside of town and then a car would be useful.
In Southern California, driving a car is by far the fastest, easiest way. This is especially true for remote mountain communities like Julian. Our mountain roads are also great fun on a motorcycle and can be challenging for bikers. It's best to ride your bike on weekdays, as the traffic is much lighter!
The San Diego County Transit System Northeast Rural Bus Route 878 serves the Julian area once per day in each direction. Call (760) 767-4287 for reservations and schedule details.
Again, a car is the easiest way. There are also excellent mountain bike, hiking and equestrian trails and many of the major roads DO have bike lanes, but these 'lanes' tend to taper into nothingness around corners. Keep your eyes open and bike at your own risk, especially during busy weekends!
For a little back-country adventure, guided Llama Hikes and gourmet wilderness picnics can be scheduled with Leelin Llama Treks -- 1-800-LAMA-PAK -- http://www.llamatreks.com
R&B Bicycle Club offers numerous mountain bike excursions -- (760) 765-2200 -- http://www.julianbikes.com
Sky Sailing in Warner Springs offers gliding adventures and glider pilot instruction -- (760) 782-0404 -- http://www.skysailing.com