Lurking in #screen on freenode is paying off. I found out today that you can set your GNU Screen window titles automatically - so, while you are running a command, the title changes to that command. This will help when changing windows (such as when using the window list bound to C-a " by default).
This requires two things: first, your shell has to send an escape code as part of the prompt. With bash, there's a convenient spot in the default Debian .bashrc where $PROMPT_COMMAND is set depending on $TERM. Add a new case for 'screen', with:
PROMPT_COMMAND='echo -ne "\033k\033\134"'
The second part is to add a line to .screenrc:
shelltitle "$ |bash"
Where 'bash' is the default window title. This assumes that your prompt ends in "$ ".