I used some similar I2C RAM in an old project (
https://www.youtube.com/watch?v=bGJX3UzEtss). It's cheap, but there are 2 problems:
- it's super slow
- you can't directly address external RAM with the atmega328 (atmega2568 can, see
http://andybrown.me.uk/wk/2011/08/28/512kb-sram-expansion-for-the-arduino-mega-design/)
...but actually I planned to put some I2C RAM in the universal module to come (extra RAM, vibrator, wireless com, extra I/O, L/R buttons, RGB LED, etc.).
Thanks for the link, and welcome on the forum!