Baden Powell is a great hike. Leave about a half hour before sunrise and you can make it up to a bench that faces east. Have a seat, break out some gorp, and watch the sunrise. It's awsome. Continue up to the top before the heat sets in and be back home by 10:00. A great way to start the day.
Clint is right about the Dawson Saddle trail. This is a very pleasant trail that gains elevation very gradually. It's a bit longer than the Vincent Gap trail, but much easier. A pretty neat experience on this trail is being buzzed by gliders. Some of them fly so low to the top of the ridge that you can see the pilot looking at you.
Rickster, if you're looking for hikes with water, it's best to go from the Vincent Gap parking lot down to Mine Gulch. Even last October, after a pretty dry year, there was plenty of water down in the gulch. This area sees very few visitors, so unlike the Baden Powell trail, you can pretty much have the place to yourself. There are some very pretty areas down there. The problem with this hike is that it is an "upside-down" hike. You go down first, then come back up the trail when you're already tired and possibly sore.
The Acorn trail is fun, and you are almost guaranteed to see big horn sheep if you continue up the Pacific Crest Trail for another 1/2 mile or so. Keep looking down slope. Listen carefully and watch for dust clouds where sheep were startled by your presence and ran away. They are always aware of you before you are aware of them. To make this into a day hike, find the trail that goes up Pine Mountain. This is a narrow ridge that you won't soon forget. It may still be icy.
Have fun.
