MOD: See the discussion in this thread on Adobe Community Forum. Adobe might not be giving away free, and downloading & installing CS2 might not be legal if you are not already a valid licensee.

Update: Adobe released a statement via their blog:

Effective December 13, Adobe disabled the activation server for CS2 products and Acrobat 7 because of a technical glitch. These products were released over 7 years ago and do not run on many modern operating systems. But to ensure that any customers activating those old versions can continue to use their software, we issued a serial number directly to those customers. While this might be interpreted as Adobe giving away software for free, we did it to help our customers.

Adobe is giving away free programs with full access

Not sure how long it will last

Must register for FREE to access page

After you sign in, the page will show the download links with the serial number for each product

Products to be given away are: