How do you want to dispose of it? If you are selling/giving it away I would: 1) use a secure erase program on it 2) use fdisk and destroy ALL partitions 3) create a new partition 4) format the partition to it's fullest capacity and 5)again use fdisk to destroy the partition.
If you mean disposing of it to the nearest trash heap, use a big hammer, cutting torch or your fav way of destroying things on it. Oh ya, a large, powerful magnet works wonders also. Physically destroying it is what you are after!!!