My first AAdvantage number (I still remember it!) was used for EAASY SABRE on CompuServe back in the auld days... on my 486DX 50, with a beautiful ViewSonic 14" display and 14.4 modem.

It lay unused for flights for so long that, when I took my FF accumulations from AS to AA, I had to get a new number. I kept using it when it was available as a weird Frankensteined Internet web/text amalgamation, and was very sad when it went the way of the dodo.