1) sleep-in and recover from your hangover
2) win some money on the table and get your buzz going again with the free drinks brought around
3) go to the straosphere (they should give you free entry with the contiki pack)
4) go to the Karnival Tent next to Harrahs for a good afternoon sesh. Hopefully the Whip-Its are playing, they put on an awesome show.
5) if you have a bit of free time, go check out Freemont St. It's better at night if you have a spare night.
6) Go do the Grand Canyon chopper flight if you haven't been there before...
7) Grab more drinks in the form of yard glasses/boots/eiffel towers filled with daiquiri
Hope that helps, enjoy!