If you are not using a GROUP variable, one alternative is the following:
1. Assign the Y variable to both the Y and the GROUP.
2. Turn off the tick value labels using the DISPLAY option on the ROWAXISOPTS
3. Create a DISCRETELEGEND and assign the scatter plot to it.
The end result is that your axis values will appear in the legend next to the appropriate scatter symbol and your plot will reclaim the horizontal space. In SAS 9.3, there is an AXISLEGEND that will let you do something similar without having to use a GROUP variable.
Hope this helps!
Dan