I still like:
	for x in list:
	    if x < value: 
		do_something
better than 'filter' for both clarity and effeciency. 
The major desire for getting the test on one line is in 
interactive use - especially with readline's ^P, ^H to 
scroll back thru commands. It's a lot nicer to get the
selection, at least, one one line, if not the whole command. 
[ But I suppose all you Gnu-wizards out there do everything
  from within emacs! ] 
In a module, sometimes it would be nice to avoid getting too 
indented, but I can live with that. In 'C', you can usually
go by the rule that if your code is getting too indented to
handle, then it's time to extract some of it into a function. 
With Python's 'mandatory indenting', I find this rule a little 
harder to follow. When I'm at an X-window, it doesn't bother
me much - I just strecth my xterm a little wider. But when 
I'm editing at home, I find myself stripping extra spaces 
between function arg's and list and tuple elements to be able
to read everything in 80 cols. 
- Steve M.