plotting from command line R

Sorry if this is a newbie question, but I'm trying to plot in R  
from the command line (not the aqua console).  When I do a very  
simple plot in the aqua console, everything shows fine, however,  
when I try from the command line version of R, I don't see window  
pop up and I get no error message.  I'm sure I just need to change  
a setting or something.  Has anyone else run into this?  I'm  
running OS X 10.4.6 and R 2.3.1.  Any help would be greatly  
appreciated.  Thanks.

R GUI uses Quartz device which is not available in the command line  
version of R, because it is embedded in the GUI. Therefore the  
default is to use X11 if available and fall-back to PostScript if  
it's not. From what you describe you are not using X11, so your plots  
go to the PostScript device by default. Just type
getOption("device")
to see which device is being used. If you want to use X11, then make  
sure your X server is running and you set DISPLAY properly (either  
start R from xterm or if using Terminal DISPLAY=:0.0 usually does the  
trick).

Cheers,
Simon