I'm not sure about Yahoo Maps (beta).... I just doodled around with it, and can't get it to print large. The only thing I could suggest, is to get your map displayed on screen just how you like it, then do "CTRL + PRINT SCREEN", and then open up Windows Paint (or Photoshop, Jasc PaintShop Pro, etc...) and then "Paste" the image. From there, you can print it however big you want.

Butch A.