Hi folks, I began working on a transliterated version of the BGT over the Christmas Holidays in response to the discussions on the forum. I just finished a provisional version of the "GRT" (GReek Bible Transliterated). The file is available at the following URL: http://oldinthenew.org/bibleworks/GRT.1.1.zip.
The transliteration scheme followed here is the one given in the SBL Handbook of Style, with one modification. The macrons used to distinguish eta's from epsilon's and omega's from omicron's have been replaced by circumflexes above the appropriate letters (Perseus & TLG have similar transliteration styles). The copyright file (GRT.bww) in the zipped folder has a complete transliteration table.
Please report any errors to http://www.oldinthenew.org/emailform.html. I am also open to any suggestions for tweaking the transliteration from any Greek grammarians out there!