Yummygum has previously shared a set of 60 free PSD vector icons, IconSweets.

IconSweets2 is another collection of 1000+ high quality free PSD vector icons, perfectly suitable for iPhone & iPad apps or for your new web project.

It contains 400+ icons both in 64×64 and 32×32 and 292 icons in 16×16, all created as vector Photoshop shapes. You may use these icons for both commercial and non-commercial projects and customize them any way you like.