To manually affect the speed for a rapid traverse there are a couple of methods.
First, Insert a M48 command at the top of the program, then you can controll all rapid movements with the feed rate knob.
Second, locate the G00 command, the use the Tab editor (press the Tab key) to change the code to G01 and add a feedrate on the same line, such as F400. You can also use the Editor to replace all G00 commands with G01 F400.
With regards to Brads question about how are you programming. If you are using a CAD/CAM system, then you may need to update the Post Processor to include a M48 command. It's possible, you may want all of the G00 commands changed to G01, so you may be able to do that with the post processor also.