like most things, it's been done by some9fan somewhere somewhen. here's a simple transliterating eng-bg:bg-eng dictionary that queries a remote site:
http://mirtchovski.com/p9/sadict/sadict i don't think it was ever submitted to slashdot because it's just so simple. on the other hand i'm contemplating submitting this XML data file that consistently makes my machine unresponsive and takes a few hours to process. now that's serious computer science right there!