How to make a time stretch effect like Aphex Twin

Everybody loves AFX, You can't write electronic music if you have never heard of him.
(Unless you are Basshunter or Eric Prydz.... shudder).

Here is a video on how to recreate that sound in Reason, But the same rules apply in whatever DAW you choose to use.

But remember, Don't just emulate the AFX sound, Learn it and develop on it, There is too many copy cats!