I've had a lot of ideas over the years for songbook replacements. None of which I have implemented but only dream of.
Large laminated posters on the walls with the entire songlist. (lighting may be an issue) The beer distributor has comitted to printing these free with ads for their products.
Acrylic covered tabletops divided by Genre. (put the heavy metal guys in the back)
Extra comp/laptop to do searching from possibly linked to the show comp with a messaging system. (breakable hardware could be enclosed with lexan and use waterproof keyboard/mouse) I do forsee some people "hogging" this.
Old palm pilots with custom linux distro and a read-only PDF file to search from. (I still like this one if anybody has the SKILLZ) I have found these as cheap as $10 if bought by the dozen.
E-book readers. (expensive hardware that can be broken/stolen)
The latest is a cell-friendly searchable web page. They provide the hardware and you only need to keep the list updated.
I could see one of you enterprising young men setting up a hosting service for this one. Front page, pick your bar. go to list and search away. Fuzzy logic on search for illiterate and/or drunk people. Put ads on the page or charge the venue an annual fee.