the following things are safe to delete:
C:\Windows\Installer
C:\Program Files\Adobe\Adobe Bridge
C:\Program Files\Adobe\Adobe Help Center
C:\Program Files\Adobe\Adobe Stock Photos
C:\Program Files\Adobe\Adobe Utilities
C:\Program Files\Adobe\Adobe Photoshop CS2\Samples
C:\Program Files\Adobe\Adobe Photoshop CS2\ImageReady.exe
C:\Program Files\Adobe\Adobe Photoshop CS2\Scripting Guide
C:\Program Files\Adobe\Adobe Photoshop CS2\Helpers
C:\Program Files\Adobe\Adobe Photoshop CS2\Help
C:\Program Files\Adobe\Adobe Photoshop CS2\Required\ImageReady Default Actions
C:\Program Files\Adobe\Adobe Photoshop CS2\Plug-Ins\Adobe ImageReady Only
C:\Program Files\Common Files\Adobe\Linguistics
C:\Program Files\Common Files\Adobe\Color\Settings\ExtraSettings
C:\Program Files\Common Files\Adobe\PDFL\6.0
C:\Program Files\Common Files\Adobe\PDFL\7.0
C:\Program Files\Common Files\Adobe\Spelling
C:\Program Files\Adobe\Adobe Photoshop CS2\AdobeUpdater.dll

anything in C:\Program Files\Common Files\Adobe\Color\Profiles\Recommended that you think you don't need

note: do NOT delete the Activation directory -- the files in there don't do anything, but Photoshop will not start if it's not present.

note: if you delete c:\windows\installer, you'll need the original .msi file to uninstall Photoshop (and anything else that uses .msi files).

note: after deleting, you may get "could not complete your request because of a program error" on photoshop startup. This is normal -- photoshop is trying to run automatic updates.

total space saved: 357MB