A quick search at versiontracker.com for 'desktop' yielded all of these desktop icon position utilities - and i'm sure there's more if you feel like searching further.
Desktop Icon Manager 1.3.1 - keeps desktop icon positions fixed when switching resolutions
Desktop Magician 2.0.1b1 - Save & restore icon positions, windows, apps & more
Desktop Resetter 2.2.1 - restores position/size of desktop icons/windows if they're rearranged
DesktopDemon 1.3 - tool to save desktop theme, icons & window settings
DesktopMinder 2.0 - "save sets of arrangements for apps, folders, aliases, or desktop items"