Check out Bundle::XMMS over at CPAN. It can control the XMMS multimedia player. I used it quite successfully a while back to drive an MP3 alarm clock. It would come on quietly then slowly increase the volume until I got up and shut it off.

Update: Also check out Audio::Play::MPG123 and MPEG::MP3Play. I have not used these modules so I can't say much about them.

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IndyZ