This may be old news but I just found it so I thought I'd share. Copy the attached file to your "plug-ins" folder (at the root of Sketchup) and when you start up Sketchup look at the Plug-ins and you should see a Cutlist option. The way to use it is to select a group of parts (I just select the whole piece) and go to plug-ins/make Cutlist. It creates a list of parts and the sizes. From there, it may be imported into Cutlist. By the way, I did not create this file, someone else did.
get file here