SHORT:
Try Ian Henderson's
Megazoomer which inserts itself into the Window menu of your apps, and will quickly hide the menu/dock and zoom the active window to full screen.
LONG WINDED:
It's a
SIMBL plugin and at v0.3, so if you get a bit antsy about alpha/betas and these sorts of system extenders, I guess it's not for you (they've been harmless in my experience.)
When full-screen, the menu bar auto-shows (like dock auto-show/hide) and your app's toolbar remains (but you can hide that in the normal way for a given app, if you want.) The other nice thing is that window drawers work properly -- with NWX go to full screen then hit the Tool Drawer button and the full-sceeen window narrows just enough to show the drawer (and hiding it will return the window to full-width.)
IMHO this is well worth the price (free) -- it's a great addition to your system, and it allows me to stop bugging Nisus, Omni et al to support my little pet feature.
Full-screen viewing seems to be coming into it's own recently... well a bit, anyway(!), I guess it just goes to show how much influence Apple really has; before they started adding it to iApps, you were a bit of a loon for wanting it, now it's 'what all the cool kids are doing'.
...not you guys though, just speaking generally.
Some might argue that it's best suited to graphics apps or browsers (Photoshop's had it 'for eva' and IMHO it's one thing WinIE did right), but it can be useful in reducing clutter, and aiding concentration... and it's very handy on laptops -- I don't use it so much on large desktop monitors, but on Mac/PowerBooks and iBooks in particular, it's very nice indeed.