iconfactory, go there and atleast look, they have some crazy icons that you could EASILY turn into .png's for the springboard, and the best part, they're already grouped and waiting for plucking... just find a theme you like, or icons from different themes and have at it, i've been going through pages of icons, and theres something good on every page...

ITS ALL FREE, download their pixadex app to keep track of them and export them in .png format, you can even pick a size

^^that app is free, so long as u stay under a certain number of icons(hundreds), and even then its cheap

ENJOY