[SOLVED] Is there anyway to have a filesystem-like facility on ESP8266?

The File class won't be available on ESP8266 as there's no filesystem library built in.

By far the easiest (IMO) for small amounts of data would be to just use this library: http://www.espruino.com/FlashEEPROM

For it to 'just work' you'd either want a 'cutting edge' ESP8266 build (so newer than 1v85), or you can hard-code the start address with:

var f = new (require("FlashEEPROM"))(0x076000);