Hi!
I recently made a little script that renders the current blend in the background, so you can continue working on it while rendering a test.
If anyone is interested, I might post it online.
Martin
PS: it uses the os.spawnl() function and calls blender by command line, so it should be very cross platform.
Nice idea 
Could be interesting (/me currently save and runs from command line by hand )
Stefano
yes, of course, you can do it by hand, if you want to type the path to the .blend and all the arguments by hand. 
The script comes with a very simple GUI. Just press the Anim button to render in background, Esc to exit.
I’ll probably post it tonight.
cheers,
Martin
http://www.geocities.com/theeth/examples.html
there you go 
just change the BlenderPath = … line to point to the right directory
Enjoy!
Martin
Neato idea! How 'bout a script that also generates a couple of render slaves in the next room at the same time as well? I’d need a couple of extra boxes…