Rael Dornfest wrote an article for MobileWhack explaining how to make your Nokia 60 Series phone fully utilize MMC expansion memory. As Dornfest says:
You need to be sure that your phone is using the MMC card rather than its onboard storage for about anything it’s installing or saving. The Series 60 does not, unfortunately, have some central “Prefer MMC to Onboard Memory” switch to throw. You’ll need to tell individual apps to do so individually.
Two weeks ago, I mentioned the substantial deals on the Nokia 3620 and 3650 available at Amazon.com. Those incentives are still available, if you are interested.