i happened to try this sometime back. logging off and proper IM delivery seemed to pose great problems while using yahoomulti.
hello fella sprint user…yahoo on sprint phones is pretty bad. ive been using wireless web(and now Vision premium). I even tried the newest Y! midlet. the midlet requires lots of improvements. its still in the infancy stage. No status messages. Missing IM notifications…so many things about it. well here is a plugin for GAIM that seems to support one way SMS delivery. I never tried it myself. I havent played around with from my linux box a lot yet.
http://www.yhbt.com/staticpages/index.php?page=gaimsms
let me know if you know of better ways to get your yahoo IMs on your sprint phone.
IM forwarding for Sprint PCS phones!!