The R package ETLUtils is now available for download at it's CRAN repository.
It's a package which facilitates the ETL in situations where you need to interact with SQL databases in a corporate environment. Basically it currently focusses on the E(Extract) part of the ETL.
In the libary you'll find a function called read.dbi.ffdf which allows to extract easily large datasets from an SQL database through DBI straight into a ffdf (part of the ff package). This should ease the usage of the ff package for working with large datasets in corporate environments where you need to interact e.g. with MySQL, PostgreSQL, Oracle through the package RMySQL, RPostgreSQL or ROracle without having to worry about RAM issues when importing large datasets.