A lot of usb mice I bought in the past came with a usb to ps/2 adapter. I threw them all in the trash unfortunately.
Heh. Never ever throw away any extras like cables you have leftover from builds. You never know when you'll need them.
You could call up independent computer shops which recycle and take in old computers or even second hand stores.
Anyone know where I can find a cheap PS/2 keyboard (NOT ONLINE, but IN-STORE)?
If you can find them at Goodwill,a perfect PS/2 keyboard would be a classic IBM Model M.
(Sorry,I'm biased,as I own 3 IBM Model M keyboards- 2 1991 vintage,and 1 1995 vintage.)