[icor1031]

For a standing man who's 5'8", what's the best height for a work table?

 

[cabinetman]

For a standing man who's 5'8", what's the best height for a work table?

Average height is about 34". You can set up a mock top at different heights and get a feel for what's comfortable. Some work tables might be convenient if they were the same height as your saw top.

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[woodnthings]

depends on the "work" to be done

Assembly work, carving, sitting on a chair or stool is different than hand planing a surface and handplaning an edge can be different also.
Heavy work that requires downward pressure, will go better at a lower than average height. I'm 5' 11" ...now. :blink:
My work bench with vises is 31"
Table saw and outfeed table is 34"
Router table is 36"
14" Bandsaw is 37"
Radial Arm Saw is 39"
So, it all depends on the type and the scale of the work to be done.

OR you can do this:

 

[icor1031]

Nice idea, mate. Here's a video I just found,

At the end of the video, he screws something to (obviously?) keep the legs from moving.
What might he be using?

OR you can do this:
Workbench Design Idea and Plans - YouTube

 

[Tman1]

Nice idea, mate. Here's a video I just found,
Video Link: http://www.youtube.com/watch?v=LKUVgv_iLtM

At the end of the video, he screws something to (obviously?) keep the legs from moving.
What might he be using?

It looks like some type of thumb screw. My guess is that he has something like a t-nut on the outer part of the legs and some type of clamp pad on the end inside the leg.

 

[CaptainMarvel]

For a standing man who's 5'8", what's the best height for a work table?

The "best" height is whatever you are most comfortable working with - though, in my opinion, you should consider comfort level for both standing and sitting (on a stool) at the table.