[R] memory management in R

[john]

I have volunteered to give a short talk on "memory management in R" 
   to my local R user group, mainly to motivate myself to learn about it. 

The focus will be on what a typical R coder might want to know  ( e.g. how
objects are created, call by value, basics of garbage collection ) but I
want to go a little deeper just in case there are some advanced users in the
crowd. 

Here are the resources I am using right now
  Chambers book "Software for Data Analysis" 
  Manuals such as "R Internals" and "Writing R Extensions" 

Any suggestions on other sources of information? 

There are still some things that are not clear to me, such as
  - how to make sense of the output from various memory diagnostics such as 
        memory.profile ... are these counts? 
        How to get the amount of memory used: gc() and memory.size() seem to
differ
 -  what gets allocated on the heap versus stack
 - why the name "cons cells" for the stack allocation 

Any help with these would be greatly appreciated. 

Thanks greatly, 

John Muller