"ten13th" design for the Replicator 2X was just so good I made a version for the Replicator 1 Dual. And while it isn't a big fan it does blows just where you need it.
I combined "ten13th" nozzle design with minor mod's and acetone glued it to "Fan Guard with Deflector" http://www.thingiverse.com/thing:31801
I modified the nozzle to give it a larger area on the back to glue the two parts together.
Using the Fan Guard allows for easy removal without needing an allen wrench
The only problem is it blocks the hypnotic view of your creation being made.

UPDATE #1
Found a problem with extra-long dual color prints. (Both Extruders HOT)
As you can see from the fifth picture, even with ABS the nozzle is too close to the hot extruders. I'm now insulating the nozzle with double sided foam tape and aluminum foil, and making sure I remove it whenever active cooling is not needed.

Using Replicator 1 Dual
Printed by RepG/Sailfish Ver 40/r22
ABS Extruder 220 / Platform 110 / Enclosed
Object Infill: 10%
Layer Height: .20
Number of shells: 1
Feedrate: 40
Travel Feedrate: 55
Print Temp: 220
Printed on glass with hairspray

Glue the two halves of the nozzle together.
Important TEST fit the Fan Guard and Nozzle and mark where you want to glue them, there isn't allot of clearance.
Then glue the Fan Guard and Nozzle together.