Congrats if you own the very nice Samsung Galaxy Nexus with Ice Cream Sandwich!  I purchased mine from the Google Play Store.  When it comes to screen capture on your Galaxy Nexus, it’s pretty easy on this device and does not require Rooting(XDA Link). HOW TO SCREEN CAPTURE SAMSUNG GALAXY NEXUS: Press and hold the VOLUME DOWN AND POWER [...]

read more: How To Screen Capture with Galaxy Nexus (No Root, HSPA+,ICS)