kinda depends how far you want to travel on and off the lake. the lake alone offers a lifetime of opportunities. more shoreline than the continental west coast of the united states will do that
Josh mentioned some good sites to hit that will be close but still offer lots of time to kill.
I believe your coming down the 89 through utah yea?
some sites you can check out on the way (or way back) if you have not yet.
1. Bryce (kinda out of the way)
2. Zion (also a little out of the way)
**3. Toadstools near Paria (utah mile marker 20 or so on the 89. 1 mile round trip easy/ moderate hiking and very worth while and wont take long. http://www.amwest-travel.com/awt_gra...oadstools.html
4. Horse Shoe Bend (not on the way but just on the southern skirts of page just off the 89. short hike, great view, very popular)
1.Try Escobars in kanab for food if you happen to be hungry and for mexican food.
2. Blue Buddha in Page arizona is excelent. (sushi, tepanyaki, and other asian food)
3. Antelope Point of course as mentioned
4. Amangiri Resort (**Reservation required, so call first** Very new and high class and private resort, turn at US 89 utah mile marker 3, might be a bit pricy especially for dinner and alcohol if you drink. i work here as a driver, nothing like it.)http://www.amanresorts.com/amangiri/home.aspx
5. Corner cafe - inside the lakepowell mart/ sinclair station at greenhaven on the boarder of arizona and utah. closest restaurant to lone rock. unadvertised but very tasty. they do sandwiches and pizza
other lake sites.
1. Warm Creek - the place of the original Bro-stock (northern end of)
2. antelope canyon. name sake of antelope point
3. Navajo canyon - one more canyon up from antelope, very wide and deep canyon.
4. Padre Bay - Just plain awesome and full of history.
5. Rainbow Bridge - far up lake but the number 1 attraction
... there are many many more things that can be added to each category above