Hi,
> We recently bought a retirement home, but it will be a year or so  
before we can move in
> -- leaving the place uninhabited most of the time.  I'd like to  
install an inexpensive (under
> $1000 for parts -- I'll do the installation myself) CC-TV   
("CC"="closed circuit") and recorder
> that can be connected to a Linux-based computer I can access over  
the Internet.
you can use ZoneMinder
http://www.zoneminder.com/
with or without DVR (ZoneMinder itself can act as video recorder).
Zoneminder has a lot of features (e.g. Motion Detection, Trigger,  
email delivery..), and a wui - web user interface.
It supports lan streaming (e.g. Ip Cam, Video server) and usb cam.
Or, if you want to save more $$, you could use also something like  
this:
http://icamview.com/
that convert usb camera in ip camera, providing Motion Detection,  
email delivery, ftp upload...
My 2 cents
Regards
M