Hi - We'll be in Monterey third week in August and will have time to travel down to Big Sur. Any suggestions for what to do on a day trip?

The drive alone from Monterey to Big Sur is absolutely spectacular. I would recommend dinner at Sierra Mar, the restaurant at the Post Ranch Inn. Another good choice would be Nepenthe.

The pictures I have seen of the CA coast near the Big Sur area are breathtaking. Do you think the scenery is comparable to that which is found in Hawaii?

The main thing to do is just enjoy the scenery. I would recommend the 17 mile scenic drive between Monterey and Carmel. It is well worth it. The major attraction, apart from the scenery, is Hearst Castle.

For a day trip from Monterey, I would suggest leaving very early in the morning assuming that there is no fog. Travel all the way down the Big Sur to San Luis Obispo and then return back on 101 to Salinas and cut across to Monterey. It is a very ambitious daytrip and won't leave a lot of time for stopping. However it is doable though I personally would stay the night in San Luis Obispo and return the next day.

Bill & Karen: Do a search on this forum with the words "California coast" and you will find a trip report from my recent drive from LA to Monterrey which has lots of detailed recommendations on it. In short I would recommend:
1. Stop at Pt. Lobos State Park south of Carmel -- get out for an hour or so and walk some of the paths -- it's gorgeous.
2. Allow LOTS of time for the drive down the 90-mile Big Sur coastline -- it takes much longer to drive than you'd think, because it's very curvy, and sometimes there's lots of traffic.
3. Drive at least as far south as Ragged Point, which is a great place to stop and walk behind the restaurant to see the view up and down the coast.
4. Better yet, if you can manage to make it all the way down to Hearst Castle, it won't disappoint. However, if you don't have the time to take the 2 hour tour of the place it is not worth driving all the way down there because you can't really see anything unless you take the tour. If you do take the tour, make reservations in advance (www.hearstcastle.org) -- it is worth it.
5. You said you can only do a day trip, so I'm assuming you can't stay overnight. However, if you can stay overnight, I would not go down as far as San Luis Obispo as the previous poster said. Cambria is a great little town just a few miles south of Hearst Castle and that's where I'd stay if I were you (but you said you could only do a day trip, so I assume you can't).
Have a great time!

Also recommend the 17 mile drive and stopping at Pt. Lobos Park. The scenery is outstanding, but don't do it in a very foggy day or you won't see much. To save time, I would also drive down Hwy 1 and back up on the 101 freeway. Watch your speed on 101 however-it's a known speed trap! If you only get to the town of Big Sur and have lunch at Nepenthe, you will have gotten a good feeling for what Big Sur is like. Enjoy.