PalmOne devices usually use different types of accessories than the Sony Clies. No only the form factors are different for cases, but the expansion medias are very different. Clies use Memory Sticks while most of the Palm use SD (Secure Digital) cards.
I went from a Sony T665C to a Palm Tungsten|T3 and had to get all new accessories. Unless you have an IR keyboard, ear buds for the MP3 player, or generic case, I don't think that you'll find any accessory commonality between Sonys and Palms.