Las vegas or hollywood vacation ideas & things to do?

I'm going to Las Vegas and Hollywood on a vacation in 5 days.
does anyone know any really fun stuff to do in either places for teenagers-young adults?

I've been to las vegass, you really want to see a shower andd most deffinatly at night time go to the new york new york and ride the rollar coasterr:D

I just got back from visiting my daughter in Huntington Beach, Ca. She's 21 years. old and loves living there. I had a great time visiting... this area is about 45 min. away from Hollywood. Check out the surrounding areas : Newport Beach, Huntington Beach, and Laguna Beach (beautiful). Huntington is known for it's surfing and goes by the nickname, Surf City. Lots of people your age. Have a great vacation !