windows xp - What is the fastest way to securely overwrite an old hard drive?

I'm going to give my HDD away, so I'm writing it full of crap so there is no possibility to recover any of my files I had there. Although, I have heard even re-written drives can be recovered some data from them, but I don't consider a high tech guys ever touching it, unless its very easy? I would like to know if it's possible... and how many times I need to write it over?

On the real question here; could it be possible to write into the multiple disks inside the HDD simultaneously and thus increasing total data write rate? So lets say if there are 6 disks inside, I could get 6x write speed if I wrote the same data to each one of them at same time.

Any other suggestions are welcome, since I am writing with 22MB/s speed ATM (old drive, or crappy code?), this will take a while.

Edit: For a security note, my HDD is around 10 years old, or less, and 60GB in size. Does this need only one wipe?

Answer

I used CCleaner a few times, which is a free tool that does the job.