I recently bought one of those cheap chinese component testers on ebay, and designed a case for it.
My goals were to keep it as small as possible, while still keeping enough space to add three 2mm Connectors in order to use the tester with external cables.

It should fit three of those (I have not ordered and tried them yet!): http://www.reichelt.at/Buchsen/MBI-1-AU-SW/3/index.html?ACTION=3&GROUPID=5621&ARTICLE=128912&OFFSET=16&WKID=0&

The 9V battery snaps in place and sits firmly, without moving even a bit. The whole case can be used without any screws, but I would recommend mounting the PCB with at least one screw.

The screen is lowered a bit into the case in order to protect it from scratches and other mechanical damages.

Files:
lcr_top - lid of the case
lcr_bottom - bottom of the case, with three holes for the three 2mm connectors
lcr_bottom_noholes - bottom without holes for connectors