Though bigmemory, ff, and other big data solutions (databases, etc...)
can help easily manage massive data, their data objects are not
natively compatible with all the advanced functionality of R.
Exceptions include lm and glm (both ff and bigmemory support his via
Lumley's biglm package), kmeans, and perhaps a few other things. In
many cases, it's just a matter of someone deciding to port a
tool/analysis of interest to one of these different object types -- we
welcome collaborators and would be happy to offer advice if you want
to adapt something for bigmemory structures!