is there an application that lets you change your voicemail and txt ringer
Yes there is on place I found.
Efiko Software: ToneFXs for iPhone
yeah, but tonefx only has a trial period then it costs money to register it..
havent found a good way to change add sms ringers yet... I've been planning on going thru some more of the file system to find the folder that they are in and see what format and requirements there are, then im sure you can just ssh files into that folder.. if someone has already done that let me know.