For the retail license there is no way to obtain a license for Creative Suite 5. You could download and install the 30 day trial from http://prodesigntools.com/all-adobe-cs5-direct-download-links.html.
I have moved this discussion to the InDesign forum as the users in this forum may have additional suggestions.
I think that about covers it.
My understanding is that volume licensees can get a version downgrade, though, and that you can purchase a volume license with a single seat through the volume licensing resellers or direct from Adobe.
That is correct Peter for the volume licenses it is possible to do a backwards license to CS5. If 42mjhenry42 is regularly going to be working with Creative Suite 5 users they may want to consider returning their retail license and then working with our volume licensing team to purchase a volume license for Creative Suite 6 which has then been backwards licensed to allow them to use Creative Suite 5 instead.
Thanks for the assistance, I'm currently checking out the prodesigntools.com link provided.
Can a CS6 retail license be used to activate a trial version of CS5 or is this only possible with a volume license?
42mjhenry42 no a CS6 retail license can not activate the trial version of CS5. Volume license customers who go through the backwards license process are actually issued a CS5 serial number to use as their license.
Thanks again Jeff, I really appreciate it.
In case anyone reading this needs it, the following link describes the backwards license process:
http://www.adobe.com/volume-licensing/policies.html - CLP and EA policies section.
And the information link for volume licensing available: