Both Mellon Collie and the Infinite Sadness and Machina were released on MiniDisc but were limited to releases in Europe and Australia. The only Smashing Pumpkin release on mini disc in the Unite States was the release of the Singles soundtrack which contained the song Drown..
A number of Smashing Pumpkins shows were recorded by fans via MiniDisc. Here is a small sample
To see more pictures of the Smashing Pumpkins releases on minidisc check out SPFreaks.com