1. Porn used to get you in the mood for a wank.
2. Any pictures or videos a man can look at to assist in the wanking process. Doesn't have to be porn, can be any old picture of someone fully dressed, just as long as it gets you in the mood for a wank.
That pic of Jessica Simpson is just the wank ammo I need. See ya in a little while.
The bra ad in the local newspaper is great wank ammo.