Adobe is opening up the entire Creative Suite 2 for free download since it no longer runs technical support for them (they *are* 7 years old at this point). All you need to do is create an Adobe account (also free) and you're set! I just downloaded it myself since I can't find the disks for my old copy of CS2, and it installed and runs fine on my Mac. They warn that some systems might not support CS2 anymore, but I'm running Snow Leopard on my Mac - one update from the current OS, if I'm correct - and there's no issue that I have found yet. I haven't tested it with my tablet yet, so be prepared to fiddle if the pressure settings are weird.
(edit: aaaannnd in hindsight I realize how spammy/scammy this looks lol, but I swear I have not been replaced with a bot. The link is clearly to the official Adobe site, if that helps).