so far, every1 has been right. how?
well, computer theory is in base 2, so that answer is 1024. but math is base ten, so that answer is 1,000. how, then, do computers work?
companies selling drives/flash memory (ie hitachi, seagate, crucial, lexar, sandisk, etc) will tell u capacity of drives in base ten, or 1gb=1000mb. software/OS/ram companies (ie microsoft, apple, real, ea, crucial, etc) tell u memory/storage space necesary in base 2, or 1gb=1024mb. (due to this crazy usage, some recommend that 2^30 bytes should be called a gibibyte instead of gigabyte, but it hasn't caught on.)
so, really, the correct answer depends on ur usage.
O!!! and, do NOT confuse Gb w/ GB - they are not the same. GB is gigabyte, Gb is gigabit. because 1 byte = 8 bits, 1 GB=8Gb