I have an existing circuit that I would like to have one of the outlets switched. The only catch is I need the other outlet to stay powered at all times. I'm not sure of the best way, but I've made up a diagram of what I think will work.

Here is an existing diagram.
http://i276.photobucket.com/albums/kk1/nrs2420/misc/original.png

And here is the new diagram
http://i276.photobucket.com/albums/kk1/nrs2420/misc/new.png

Will this work?

Your wiring diagram is correct except for one thing. You must use the white wire to take power to the switch. That is so that you will have the black to connect to the outlet. Redesignate the white as a hot conductor by placing a piece of black electricians tape on each end. These things are not only the practice but are also code requirements.

Thanks, I knew about the black electrical tape on the white wire, but was unaware that it should take power to the switch.

Thanks again.