Which way do you feel is the unsafe way? Bump starting the bike or hooking up your car battery to jump the bike? Bump starting is very normal and doesn't do any damage but using the car battery, which actually isn't recommended, can cause damage. Of course using a donor motorcycle battery/motorcycle battery jumper is the best bet.
Here's some nice info taken from some sites
Jump Start The Battery From Another Motorcycle
1. Position the two motorcycles so the batteries are close enough together to facilitate the length of the jumper cable. Ensure the motorcycle with the good battery is NOT running.
2. Connect the RED clamp of the jumper cable to the positive (+) terminal on the dead battery.
3. Connect the BLACK clamp of the jumper cable to the negative (-) terminal on the dead battery, or to a grounded item on the motorcycle, such as the frame.
4. Connect the BLACK clamp of the jumper cable to the negative (-) terminal on the good battery, or to a grounded item on the motorcycle, such as the frame.
5. Connect the RED clamp of the jumper cable to the positive (+) terminal on the good battery.
6. Start the motorcycle with the good battery and wait a few minutes.
7. Start the motorcycle with the dead battery
8. Remove the RED cables first from the good battery, then from the bad battery.
9. Remove the BLACK cables from both batteries.
10. Leave the motorcycle with the bad battery running until you reach your destination and/or find a suitable place to re-charge the battery with a battery charger.
Jump Start The Battery From A Car
The procedure to jump start a motorcycle from a car is the same as it is for jump starting it from another motorcycle except for item (6). A car battery has more amperage, and the charging system for a car is much more powerful than that of a motorcycle. When jump starting a motorcycle from a car, DO NOT START THE CAR'S MOTOR because the extra power from the charging system will possibly destroy the motorcycle's charging system and could cause a fire. The car battery should have enough power to start the motorcycle without the car's motor running.
youtube video on bump starting http://www.youtube.com/watch?v=PXl3RnBWbE0