On the assumption that you've got ID3v2 tags on your .flac files (which is allowed -- the flac decoder explicitly skips them)...

peculiar:~> cat `which flac2mp3`

#!/bin/sh



echo Converting $1

echo to $2...



flac -c -d "$1" | lame --nohist --vbr-new -h -k - "$2"

id3cp "$1" "$2"

Admittedly, the lame command line could use a little work -- I've not used this script in quite a while.