Espruino-Boy?

Larger monochrome OLEDs exist.

I got my pulse measured at the hospital with a pulse oximeter with a 128x64 (I think) OLED display, with the split yellow and blue.... AND IT WAS ABOUT 2 INCH DIAGONAL! I'm sure it was using an SSD1306... Sadly, he never let it out of his sight :-/

1.3's are common, but above that, I can't find any monochrome ones.

There are some interesting displays here: http://digole.com/ (control for the digole displays is all the same, and easy.

The Digole ones seem good, but as Espruino already has the graphics capability (and I'd be making a new PCB) it seems a shame to pay extra for another MCU and PCB that aren't really needed.

Maybe I'm being a luddite, but I actually quite like monochrome LCDs. I'd happily trade a bit of contrast and response time for being able to use the device outside in sunlight.

This panel looks good, if it could be found on its own: http://digole.com/index.php?productID=907

The problem is connecting to a PCB though. The Nokia ones seem pretty unique in that they've got an elastomer (I think?) strip that means you can just push them onto a PCB. Pretty much all the rest seem to need some kind of fine pitch soldering.

(Sharp Memory LCDs can be connected by Elastomer, but then they're also insanely expensive)

I guess the other option is just to produce a much smaller PCB with 0.1" pins at the top. It'd then be possible to solder on a variety of different LCD/OLED types. That doesn't seem quite as appealing to me though - it also complicates the software... It'd be nice if games only had to be written for a certain screen size.

There is a readily available 128x64 monochrome LCDs available from ebay, the "12864" one. All over eBay, and a couple inches across. They come with the ribbon cable connector (hence, fine pitch soldering to solder down the connector), or in modules with it broken out to 0.1" pin header. IIRC controlling them looked really nasty though.