use a software called "audacity"
u can download it from
"
www.download.com"
or u can search it in yahoo : )
then open the wave file by this software..
then click export file>> then u can choose export as mp3.
2007-03-13 12:24:59 補充:
Audacity does not come with MP3 support by default. To Get this support,first download and install the "Lame Encoder" Plug-In.
http://www.edhsonline.org/other/audacity/program/lame_enc.dllref:
http://www.edhsonline.org/other/audacity/audacity_lame_install.html