Forum Moderators: not2easy
The big gun - Photoshop
The big guns little sister - Photoshop elements
The pocket rocket - Fireworks
Free armour - GIMP, Irfanview
Straight shooters - Paintshop Pro, Coreldraw.
The choice is wide so really depends on how much you need to do. For file reduction and optimisation from print ready graphics; photoshop get the thumbs up for showing little quality loss over high compression. But for creating web graphcs and keeping them low I love fireworks. Freeware GIMP and irfanview are excellent and I think all of those listed will let you batch process.
NS