I made an awesome program the other day, and I wanted to upload it to my Arduino. After clicking the upload button, some really mean dude named avr came along and stopped me. He told me:

avrdude: stk500_getsync(): not in sync: resp=0x00

All I want to do is just upload my program, but avr won't let me. He's even unintelligible, so can someone tell me what the heck he's trying to say? Is there any way I can ban him, arrest him, or simply get rid of him and his stupid message?

Translation:

Whenever I try to upload a program to my Arduino, I get this error message: avrdude: stk500_getsync(): not in sync: resp=0x00 What does this mean, and how can I fix it?