Are there any programs/utilities for the Mac that allow you to control window placement similar to the tiling window managers on Linux?
It looks like TwoUp is dead, but here are some other options:
http://code.google.com/p/shiftit/
Free, OSS, and works for me! Not exactly what you're looking for.
edit: It looks like the original project has been abandoned. However, the beat goes on at the GitHub fork!
https://github.com/fikovnik/ShiftIt
Optimal Layout, an app I developed, offers very flexible window tiling, as well as moving and resizing from the keyboard.
http://most-advantageous.com/optimal-layout/
There is an AppleScript [1] script to tile two windows side by side.
I haven't used it but apparently it works for most applications. Link [2].
You could also try your luck with FWM [3] (Finder Window Manager), it seems like they support windows other than Finder itself but I can't seem to get it to work on my MacBook [4].
[1] http://en.wikipedia.org/wiki/AppleScriptArrange from http://www.trifle.pl can do it.
I've seen the XMonad [1] window manager working on Mac OS X [2].
http://haskell.org/sitewiki/images/1/17/Screen-atomb-apple.png
[1] http://xmonad.org/BetterSnapTool [1]
[1] http://itunes.apple.com/de/app/bettersnaptool/id417375580?mt=12BetterSnapTool allows you to easily manage your window positions and sizes by either dragging them to one of your screens corners or to the top, left or right side of your screen. This lets you easily maximize your windows, position them side by side or even resize them to quarters of the screen.
ShiftIt is a free option. Assignable hotkeys to resize to different portions of the screen (Left, Right, Top, Bottom, Top Left, Top Right, Bottom Left, Bottom Right, Full Screen and Center with current size)
Just click on the big download button towards the right of the screen.
[1] https://github.com/fikovnik/ShiftItDoublePane [1] is another option in this space too. Its $2.99 on the Mac App Store
[1] http://bit.ly/doublepaneBetterTouchTools [1] has keyboard-shortcuts that work for window positioning (I use it like Cinch and get the basics - Top half, right half, left half, bottom half, full screen).
Plus, it's free.
[1] http://blog.boastr.net/What about HyperDock ($9.99 USD) ? http://hyperdock.bahoom.de/ While still not true tile enabled it brings the snap to edges and resize from Aero.
I also like Hyperdock for this feature. It also has other features. For tiling, I can drag into the 8 different edge hotspots to resize to a specific region of the screen. When I drag it out of the tile region, it snaps back to the original size. These features are not highlighted strongly in the docks for Hyperdock, I just discovered them recently.
What you are looking for are the installation instructions for XMonad:
http://haskell.org/haskellwiki/Xmonad/Using_xmonad_on_Apple_OSX
That's where the picture that litb posted is used.