I have written about how to invoke the Print Screen key in VMware Fusion before, by using the F13 key on Mac keyboards. For some reason, that seems to be a hot topic on this blog, at least by judging from the google hits. The blog post ended with "Hmm, I only wonder how I'd do if I didn't have access to my full size mac keyboard (which only contains the F1-F12 keys)". This is just what happens when you buy one of those small Bluetooth Mac keyboards. Since they have the small form factor without a num pad, there is no F13 key, only F12 and the Eject key.
Here's how to make sure we can invoke print screen without having access to a F13 key.
In VMware Fusion 2, VMware has incorporated a keyboard mapping utility in the Preferences menu item. So, invoke Preferences and go to the Keyboard & Mouse option. Make sure you have Enabled Key Mappings and press the + button. Then configure Option-F12 to be mapped to Print Screen, like in the screen shot below.
Now you are able to do a screen shot of the full screen. However, when you want to do a screen shot of the current screen, you would normally press Alt-Print Screen with a Windows keyboard. Trying this, i.e. holding down the Apple key together with Option-F12 doesn't work. For that to work you need to configure Fusion to map Apple-Option-F12 to Alt-Print Screen, like in the screen shot below.