Without an Agbay. What I've done is get some aluminum strips from H Depot. I've got a 1-1/2, and 3/4. I just bent it to from a U. Lay it on the table, slide the cake up to it. Lay your knife on top of your alum. guide, and start cutting. Cuts a perfect level cake. I still yearn for the Agbay though LOL.
It's a real good solution, though. Sounds like something Alton Brown would do.