Misi 8 GTA: San Andreas

Stop enemies from attacking your territories
At any time (until time runs out and they actually take over) get in either a cop car, firetruck, or ambulance and press R3 to start the secondary mission and then press it again to end the mission. This will make it so the attack has stopped, you keep your territory, and it will have no negative effect on your game (unlike the safe house glitch).

Barbara Glitch
If you go pick up Barbara for a date, she might say that you aren't fat enough to take her out. Instead of having to gain weight to be able to take her out, you can grab a car and a fellow gang member. To do this you have to have a Sadler and a Grove St. gang member in the car with you. When you do this, you go pick up Barbara for a date and she assumes you're heavy since the Sadler itself is heavy along with the gang member. You HAVE TO have the gang member with you, or else it will not work.