For items I need to do today but can't do now, I'll make a note or print out the email and stick it into today's Tickler folder (for example, today, 3/31, I have the "31" folder sitting out on my desk).
The only pile (for now!) on my desk is a deliverable for my manager, whose door is closed at the moment. Work stuff goes into the appropriate project folder or next-action list or my Tickler folder for the day. Stuff I can't get to today, goes into tomorrow's Tickler folder. Keeps things nice and neat, though you have to be careful not to keep shuffling papers from day to day. At some point, you have to action them.
HTH -- mike